mw&s standard procedure 425 thermite welding

ISSUE DATE: 10/17/2017 SUPERSEDED DATE: 05/12/2017

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MW&S STANDARD PROCEDURE 425 THERMITE WELDING

1. SAFETY .01 Personal Safety

a. Approved hard hats, full face shields with chin attachments, leg protection, and safety glasses must be worn by employees performing any grinding, welding, or cutting operations. High visibility safety vests are not required when burning, welding, or grinding.

b. A minimum of shade 5 eye protection must be used for cutting operations. c. Protective clothing to include approved welding gloves and leg protection, where

necessary, is to be worn during all welding and torch cutting operations. Caution must be exercised at all times to keep sparks or slag from being caught in cuffs, pockets, sleeves, under gloves, and out of shoes, eyes and ears. Where necessary, ear protectors for sparks must be worn. Employees should place themselves in a position so that they are not in the line of sparks from the torch or the grinding operation. Clothing must be free of grease, oil, and other flammable materials. When performing welding or cutting operations, employees must keep shirt sleeves rolled down and exposed skin protected.

d. All personnel must maintain a minimum distance of 20 feet from the crucible after

ignition. Prior to igniting the weld portion, they must also ascertain the most direct, clear path to escape injury should a major pour-through occur.

e. All personnel involved in thermite welding must protect molten metal from moisture at

all times. .02 Oxy-Propane Safety

The rules, regulations, and instructions contained in the Norfolk Southern Safety and General Conduct Rules are applicable unless otherwise modified by instructions in this or other procedures that must be followed. a. With any torch, leakage of oxygen into propane in the mixing chamber at the junction

between the torch and the valve handle can ignite due to flashback. Employees must carefully inspect the mating parts in the torch and the handle to prevent leakage of oxygen into the propane prior to the mixing chamber and use the proper ignition sequence (i.e. establish the flame with the propane first, then turn on the oxygen for a hotter flame.)

b. External flashback arrestors (which contain both arrestors and check valves) must be

installed in all oxygen and propane lines between the torch and hoses unless the torch is equipped with both devices built-in.

c. Oxygen and grease is a highly combustible mixture. Grease must not be allowed near

cylinders, cylinder valves, and hoses.


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d. Proper ventilation must be maintained at all times. e. Purge oxygen and propane lines before lighting torch. f. Oxygen or propane must be used only as intended. Other uses, such as blowing dust off

of clothing, are dangerous and are prohibited. g. Eliminate any oxygen or propane leaks. h. Open cylinder valves slowly. Never stand in front of any regulator when opening the

cylinder valves. i. Do not drop cylinders. j. Always use, transport, and store cylinders in the vertical position; use approved cradles

to carry or transport. k. Protect cylinder valves from bumps, falls, falling objects, and from weather. l. Cylinders must be transported in accordance with Safety and General Conduct Rules. m. Never use a cylinder or its contents for other than its intended use. n. Always refer to oxygen and propane by its proper name, not as "air" or "gas".

.03 Fire Prevention

a. Standard Procedure 130 must be followed when performing thermite welding. Maximum protection against fires must be observed at all times.

b. Welding equipment must be positioned to prevent flame and sparks from falling on

cylinders or hoses. c. Each thermite welding gang must always have on hand, filled, and ready for immediate

use one fire pump of adequate capacity. .04 Track Protection

a. When necessary to foul any track, full protection against trains must be provided in accordance with Roadway Worker Protection rules.

b. When thermite welding near a signaled grade crossing, a shunt is to be used between

the two rails at the work location to prevent the false activation


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.05 Equipment Safety: All welding equipment must be checked daily for defects. Defective tools and

equipment are not to be used. Thermite welders are permitted to dress their striking/struck tools as needed. Tools must be dressed to the contours depicted in MW&S applicable Standard Plans.

.06 Weld Grinding

See MW&S Standard Procedure 280 - Safe Abrasive Rail Sawing and Grinding Practices. 2. GENERAL INSTRUCTIONS .01 Qualifications:

A welder/helper’s qualification consists of the crew's ability to make thermite welds as required in this procedure. No thermite welding is to be performed except by duly qualified individuals who have been approved by the responsible General Division Engineer, Manager of Welding, or their designated Norfolk Southern representative. The only exception allowed will be an employee training to be qualified under these rules working under the direct supervision of a qualified welder.

.02 Rail Ends/Track Safety

a. Rail end drilling

(1) In main track, a thermite weld cannot be made within 6” of existing bolt holes. (2) In other than main track locations, joints may be welded when the bolt holes

are closer than 6” from the rail end with approval from the General Division Engineer or Manager of Welding.

b. No thermite welding is to be performed if one or both rail ends to be welded have been

built up by welding. In this type situation, the rail end or ends built up by welding must be completely removed and plug repaired before welding.

c. Rail ends must be saw cut. Only if conditions exist that prohibit the rail from being saw

cut is torch cutting allowed. Rail ends must be as square and as smooth as possible, and within 1/32" of horizontal alignment. If rail is torch cut for thermite welding, a 10 MPH speed restriction must be placed when passage of a train is permitted prior to thermite welding. A qualified employee with a working radio must observe the movement. Thermite welds must be made within one hour of torch cutting. These restrictions do not apply if the torch cut metal is completely removed by grinding or saw cutting immediately after torch cutting.


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.03 Joint Installation/Removal

a. Before the start of any weld, welders must ensure that reference marks have been made in accordance with standard procedure 260 Section 10.01 to capture rail added or removed.

b. Insulated joints are to be cut in at locations specified by Signal personnel. For reference,

typical insulated joint locations for various track work designs are shown in Figure A.

.04 Compromise Thermite Welds: The following compromise thermite welds may be made with restriction as noted below.

Compromised Thermite Welds

Compromised Weld Rail Weights Max. Allowable Difference in Rail

Height

Other Restrictions

100RE to 112/115RE 7/8" Maximum Speed of 50 MPH on 15 MGT territory or less

112/115RE to 132RE 3/4"

112/115RE to 136RE 15/16"

127DY to 132RE 5/8” None

127DY to 136RE 13/16” None

130RE to 132RE 5/8" None

130PS to 132RE 3/4" None

130PS to 136RE 15/16" None





132RE to 152PS/155PS 7/8" None

136RE to 152PS/155PS 11/16" None

a. When the difference between the rail heights is greater than that listed in the above table, the joint cannot be thermite welded.

b. A compromise thermite weld may not be made any closer than 10 feet from any other

thermite weld.


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.05 Thermite Welding on or in the Vicinity of Bridges

a. Track joints are not permitted to remain in CWR rail laid on open deck bridges for longer than 3 days except for special expansion joints.

b. When a joint falls on or within 234 feet of an open deck bridge and the timetable speed

is greater than 25 mph, a slow order will be needed. Facts to be considered in determining slow order speed are tonnage, grade, curvature, temperature, rail conditions, and tie conditions.

c. Thermite welding of compromise joints is prohibited on open deck bridges. The use of a

closely matched rail plug profile with existing CWR rail contour is required. Thermite welding of these joints should be performed within 3 days of rail installation. A slow order cannot be removed until thermite weld is tested and accepted.

d. Notify the B&B supervisor at least one day in advance of making thermite welds on any

OPEN DECK bridge. Thermite welding on an OPEN DECK bridge cannot be carried out unless a B&B representative is present for protection of bridge during the thermite welding process.

e. Open Deck Bridges – When a thermite weld is made in the unanchored rail leading into

an expansion joint (on the bridge or on the ground), or any unanchored rail on an open deck bridge, the bottom of the base of the weld must be ground to the contour of the adjacent rail in order that the rail can move through the plates.

.06 Testing Thermite Welds and Defect Repair

a. Welds are to be brush ground, if possible, and/or wire brushed to remove the mold sand,

then visually inspected by the welder or welding supervisor. Any surface imperfections are

to be brush ground out.

b. A qualified thermite welding supervisor is responsible for ultrasonically testing a minimum

of four welds monthly per thermite crew to insure the quality of thermite welding.

Qualification is approved by the Manager of Welding or Research and Tests Department

upon demonstration of their ability to ultrasonically test a weld. Additional inspections and

ultrasonic testing will be needed behind newly qualified thermite welders and thermite

welders who recently made a defective weld.

c. Welds made in tunnels must be ultrasonically tested.

d. A weld determined to be defective is to be plug repaired the same day. If extenuating circumstances prevent this, then joint bars must be properly applied, any necessary slow orders placed, and the weld plug repaired as soon as possible. Local MW&S supervision shall be notified of any defective weld left in track.

.07 Thermite Weld Identification: Each welding crew is assigned a unique number. All thermite

welders should mark their welds by steel stamping the field side of the ball. The crew number, month and year that the weld is made shall be stamped approximately three to nine inches from


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the center of the weld. If a thermite weld is ultrasonically tested, the welding supervisor will stamp each weld tested with the letter “T” on the opposite field side of the weld between three and nine inches from the center of the weld.

.08 Defective/Failed Thermite Welds

a. When division officers report defective or failed thermite welds, the crew number that made the weld, weld date, and tester that tested the weld, if applicable, is to be reported along with other required information.

b. Digital photos of any thermite welds in 132-lb rail or heavier that fails within five (5)

years or any thermite weld, regardless of weight that fails within twelve months, are to be forwarded via e-mail to the Research and Tests Dept. Project Engineering Specialist at ([email protected]). Photos must show top and side view of break, each fracture face, and overall track conditions. File size must be large enough to allow enlargement of photos to show details. Any rail failures that are requested for further analysis are to be shipped to:

Research and Tests Laboratory 8-1/2 Street & Campbell Avenue Roanoke, VA. 24013 Station 2

If shipped, the defective rail sections should not exceed 1ft. in length for each piece and must be identified with the milepost location, division, date of failure, track number, mill or manufacturer, month and year rolled, crew that made the weld, and weld date. No defects shall be sent to R&T via U.S. Mail.

.09 Housekeeping by Thermite Welders

a. All scrap thermite material and weld debris is to be removed from the work location. All scrap track material and released joint bars must be moved to crossings or stacked clear of walkway or ballast line for Line Maintenance pickup.

b. Thermite welders with crane equipped hy-rail trucks should stock pile released rail plugs

at convenient locations for pick up by Line Maintenance Forces. .10 Line Maintenance Responsibility

a. When maintenance welding is being performed, the Division Engineer arranges and provides the necessary on-track protection.

b. When maintenance welding the same weight rail, the Line Maintenance Supervisor

must provide rail as close to the existing rail contour as possible. When welding same rail sections, the height difference cannot be greater than ¼”. Head width may be blended by grinding after welding.

mailto:[email protected]


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c. Plugs required by field thermite welders are to be furnished as required by item 4.02b

and distributed to point of use by Line Maintenance personnel. When thermite welders do not have boom equipped trucks, Line Maintenance must provide assistance for placement of all plugs in track.

d. Welds must not be left on top of a crosstie. If at all possible, the rail ends shall fall in the

center of the tie crib. If a weld must be made over a tie location, ties must be re-spaced by Line Maintenance forces so that ties will be to either side of the weld. At NO time may welds be left on top of a tie plate. In certain locations such as switches where the re-spacing of ties is not feasible, plug welding may be required.

e. Any track repairs required at a thermite welding location such as replacing defective

ties, re-spacing ties, or smoothing are to be completed by Line Maintenance personnel within a maximum of three days after receiving notice. Line Maintenance is to be notified of any such repairs within 24 hours.

3. GENERAL WELDING PROCEDURE

Thermite welding kits should be kept in a rotation while in storage to ensure older material is used in a timely manner. Welders must consult the manufacture’s recommendations of the kit’s shelf life. Any material suspected of being out of date should not be used and is to be reported to the Welding Supervisor for proper handling.

.01 When used, monolith crucibles must be thoroughly dried each day before use.

.02 All molds, portions, etc. must be dry at all times. Materials which have been exposed to

moisture must be discarded. .03 All equipment must be inspected regularly to ensure it is properly maintained. Worn or

damaged equipment must be repaired or replaced. .04 If the rail temperature drops 5°F or more during the time a weld is being made, that weld must

be removed from the track. Welding may be performed after sunset when rail temperature is not dropping at a rate exceeding 5°F per hour. Temperature change must be monitored using an accurate rail thermometer or digital infrared thermometer.

.05 When thermite welding, rail temperature and movement must be monitored closely after the

start of precipitation if the rail has previously been warmed by direct sunlight higher than the ambient temperature.

.06 Do not thermite weld if the rail on which weld is being made is more than 5°F higher than a

comparison rail which has not been subjected to artificial heating. .07 Temperature will be recorded using an accurate rail thermometer or digital infrared

thermometer. Temperature should be measured on the web of the shady side of the rail using


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the clean surface of a plant weld when possible. .08 When welding in the rain or snow, all fixtures, materials, etc., are to be protected from moisture

by the use of an umbrella. The completed weld should be kept covered a minimum of five minutes after grinding is completed. Additionally, extreme care should be taken when dumping slag to ensure that it doesn’t come in direct contact with moisture.

.09 When a 5°F change in temperature or weather (rain, snow, sleet, etc.) occurs within 4 minutes

after a thermite weld portion taps, this weld will be ground and ultrasonically tested immediately after proper cool down. If immediate ultrasonic testing is not possible, the weld will be ground, joint bars applied, and the weld tested within 24 hours.

.10 Behind rail laying, do not thermite weld on the rail ribbon being laid. All rail laying equipment

should be off the ribbon being welded. .11 Shut down all power equipment standing on the track near the joint when making a thermite

weld. Necessary precaution should be taken to prevent disturbing the weld immediately after pouring when working adjacent to a grade crossing.

.12 When cutting in any plug, a minimum distance of 36 inches is to be maintained from an existing

standard thermite weld (10 feet from an existing compromise thermite weld), or 18 inches from a plant weld.

.13 If the rail end to be welded has been torch cut more than one hour prior to welding, the end

will be trimmed at least two inches back immediately prior to welding. This instruction does not apply if the torch cut metal is completely removed by grinding or saw cutting immediately after torch cutting.

.14 Attachment of the pre-heat and cutting torch to the stem must be tight in order to prevent the

leaking of gas, oxygen, or air entering the mixing chamber. .15 To ensure proper oxygen flow at lower temperatures, single stage regulators are recommended

when using liquid oxygen. .16 Propane and Oxygen gas hoses need to be “T” grade 3/8" inside diameter, preferably twin 3/8"

hose of approved material. Oxy-Propane quick connects are not to be used in the thermite welding process.

4. SPECIFIC WELDING PROCEDURE FOR ORGO-THERMIT SKV PROCESS .01 Preparation

a. Rail anchors and spikes should be removed on each side of weld where necessary to facilitate alignment.

b. A gap between rail ends is to be cut to the exact opening at the time the weld is to be


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made. This gap should be 1-1/8" to 1-3/l6"measured at the base. c. Rail end condition is extremely important to produce a quality weld. Care should be

taken to produce a straight, square, and clean rail end. All rail ends shall be prepared per Section 2.02c of this procedure.

d. If the gap is too large as measured with the maximum side of the gap gage, or when

removing a defect, a minimum length plug rail as specified in 4.02b must be fitted and welded at both ends. A large rail gap should never be closed by the application of localized heat to the adjoining rail. If the gap is closed by a normal ambient temperature rise, the weld may be made while the temperature continues to rise.

e. If the rail ends are damp or dirty, preheat the rail ends in the weld area to hand warm

condition prior to applying the mold. .02 Plug Welding

a. If welds at each end of the plug can be made prior to passage of a train and the rail temperature is rising, both gaps may be cut and the rail ends ground for welding. If this is not possible, the rail segment removed from the track prior to insertion of the plug is to be cut no more than 1-1/4" longer than the plug. This will allow the first weld to be made without trimming. The rail end gap for the second weld will be cut immediately prior to applying molds for the second weld. Vertical and horizontal alignment should be approximately correct on the opposite end of the plug prior to making weld.

b. The minimum plug lengths that may be used for thermite welding are as follows:

(1) Tangent Track (weld same day or slow order) 6 feet (2) Tangent Track 11 feet

(3) Curves up to 4 11 feet

(4) Curves 4 & over 19 ½ feet

(5) Any deviation of the minimum standard lengths must be approved by the General Division Engineer or Manager of Welding.

c. When repairing defective thermite or plant welds, the following amounts of rail from

the centerline of the weld must be removed: (1) Defective Field Welds - 9 inches (2) Defective Field Flash Butt Weld - 12 inches (3) Defective Plant Welds - 12 inches


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If above conditions are not met, a 10 mph slow order must be run until the required amount of rail is removed.

.03 Rail End Cleaning

Using a circular braided wire brush wheel, clean the sides of the rail approximately 4 inches back from the rail ends. Grind flush any raised numbers or letters in the mold contact area.

.04 Rail End Alignment for Track Alignment

a. The rail ends must be lined correctly, both in vertical and horizontal position. A 36-inch straight edge is to be used to line up the rails. On curves, it is very important to watch this alignment so that the welds match the contour of the curve. All welds need to be visually inspected for alignment to ensure that it matches proper alignment of existing rail. A crown should be imposed on the rail prior to welding which will result in a flat running surface after weld has cooled. A proper crown is obtained when both ends of a 36-inch straight edge have approximately 0.062”( 1/l6 ”) clearance above the rail head. The straight edge must be centered over rail and gap.

b. After obtaining proper crown, check the alignment of the rail bases with a 12-inch to 18-

inch straight edge. If height difference between the two rails being welded is 1/8” or less, align the webs and bases making sure that there is proper crown. If the height difference between the two rails being welded is over 1/8” to ¼”, split the difference keeping the match of the web and base as close as possible. Making standard welds where height difference is over ¼” is not allowed.

.06 Molds

a. Molds must fit the rail properly before packing. Mold fit-up is extremely important. Excessive filing should be avoided. A tight mold fit is essential. When the mold fits tightly (with sealing paste if necessary), less run-out or finning occurs. Welds with undesirable run-out or finning must be contour ground.

b. Rub or file mold, as necessary, for tight fit against the rail. Do not file until fit is actually

checked visually. Check for tight mold fit with white card paying close attention to radius under the ball and the web to base radius.

c. Where mold fit is not tight, use sealing paste to fill in gaps. Use as instructed along

inside edge, but stay out of mold interior. After clamping mold shoe, check for gaps again with card and make further adjustments if necessary.

d. Be careful not to remove too much mold in the fit-up. This would severely reduce the

collar depth. Keep mold vertical and lined up over the proper gap.


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e. On one of the mold halves, evenly file the surfaces sufficiently where the first mold half

touches the second mold half when it is clamped to rail to prevent the first mold half from pushing the second mold half from the rail.

f. The diverting plug should only be filed to fit, if needed. Proper seating of the plug

should be checked. There should be no visible air gap (visible weld cavity) on the long sides of the plug. When welding in tracks with superelevation, the diverter plug must be filed on the bottom to ensure the top of the plug is level when seated to achieve uniform distribution of molten steel.

g. Molds must be packed with a premix luting material (as supplied by weld manufacture)

on the outside to prevent the molten metal from running through. Care must be taken to ensure that moisture content of luting sand is correct.

h. Place cardboard on top of the molds to avoid any luting or foreign material entering the

mold cavity which will become a nonmetallic inclusion in the weld. For worn rail, lay the card packed in the portion bag on top of the ball of the rail prior to packing the luting material. This prevents sand inclusion in this area.

i. Prior to preheating, take the torch stem and turn the oxygen valve on completely and

blow out any loose sand particles from the mold. j. There should be a maximum of 1/16" side to side gap between the mold half and the

shoe. k. Position the universal clamp on the rail using the gap gage to measure distance from

gap. This ensures that the clamping device is centered in the middle of the shoe to apply pressure evenly. Tighten the universal clamp firmly with two hands making sure it is vertical and square to the rail.

l. Adjust the locating arms of the universal clamp to hold the mold shoes in place by

tightening the hand screws so as to apply a firm but not excessive pressure to the mold. m. Fit the slag pans to the lugs on the side of the mold shoes. n. Place a rail head protecting sheet between the mold shoe and the universal clamp and

also on the opposite side of the mold shoe. .07 Crucibles and Thimbles

a. Degradable Crucible:

(1) The degradable crucible is designed for a single use and requires careful handling to prevent damage.


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(2) The degradable crucible does not require pre-heating. (3) These degradable crucibles should always be kept in a dry environment. (4) Only use portions designed for use with the degradable crucible. (5) Inspect the degradable crucible for visible defects and foreign material before

use. (6) Place on a clean section of cardboard near the working area, pour the portion

into the degradable crucible, and prepare an igniter.

b. Monolith Crucible:

(1) The monolith crucible is designed for a life of 30 welds. The crucible is ready for use by adding an extension ring and clamping ring.

(2) Always dry the crucible prior to use by heating the inside with a soft flame for at

least 10 minutes or until the outer shell of crucible, top to bottom, reaches 212°F. A temperature indicating crayon or digital laser thermometer may be used to check for proper temperature.

(3) After approximately 15 and 30 welds, the crucible should be cleaned of all slag.

Minor cracks are repaired with the crucible paste mixture supplied by the weld manufacture. Dry completely after making repairs.

(4) Never continue to use a crucible when the metal ring in the bottom is visible.

Also, discontinue using a crucible that exhibits a red spot when hot at any point. (5) The complete crucible assembly is placed on the crucible stand and aligned so

that the bottom of the crucible shell is approximately 1 inch above the top of the mold.

(6) After properly adjusting the crucible, the automatic tapping thimble and

plugging sand is added. (7) Thoroughly shake the weld portion in the bag to assure a homogenous mixture. (8) Slowly pour the portion into the center of the crucible on top of the thimble,

being careful not to disturb the plugging sand around the thimble. If the plugging sand is disturbed, a thimble bypass (premature tap) or a long tap may occur. Cover the crucible with the crucible cap.


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.08 Preheating – Orgo-Thermit SKV General

a. For all rail sizes, the preheat torch is positioned above the running surface of the rail at the height specified in Table I making certain the flame is centered over the rail gap and vertical with the rail.

b. Typical preheat times are as shown in Table I (below). Length of preheating time is also

dependent on weather conditions. c. Constant observation must be made after the minimum preheat times to ensure

sufficient preheat and no rail end melting. Refer to Table I for minimum preheat times. If the webs on both rail ends show good color (orange-yellow) over their length, the rails are properly heated and ready to weld. Only shade 5 lenses or shield should be used for observing proper rail end heating.

(1) A stop watch must be used for verifying all times.

SETTINGS and TIMES FOR SKVMINUTE WELDS

Torch SKV Torch (2 rows holes)

Torch Height 1 1/3” above rail

Typical Preheat Time: Rail ≥ 119-lb Rail < 119-lb

6.5 – 8.5 minutes 5.5 – 7.5 minutes

Pressure Settings at Torch: Oxygen

Propane

65 psig 15 psig

Flame Height 7/8”

d. Preheat Torch: Pressure settings are those required at the torch with the preheater

attached and lit. Check gages are available for checking these pressures. Pressured at the torch must be as specified in the table above.

e. Place the preheater torch in the saddle and adjust in mold for location. Preheater torch

must be centered and square with the rail. Remove assembly from mold. f. For preheating, open the oxygen valve completely and adjust the propane valve so that

the blue flame tips are of an even length as specified in the table above. Recheck oxygen and propane gas pressure and adjust as necessary.

g. Briefly preheat both slag pans to ensure they are dry. h. Insert preheater torch and saddle assembly in mold.


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.09 Ignition

a. Preheat the diverting plug by holding it with tongs above the flame exiting the riser hole. Heat for a minimum of 30 seconds taking precaution not to allow the plug to turn white (indicating overheated).

b. After removal of the pre-heating torch insert the heated and dried diversion plug into

the mold. When using a degradable crucible, place onto the mold shoe brackets. If using the monolith crucible, swing into position over the mold.

c. Within 15 seconds after removal of the preheater torch, the igniter is lit and inserted

into the center of the welding portion 1 inch until free-standing. d. After inserting the igniter, all personnel should move a minimum of 20 feet from the

crucible until the weld taps and pours into the mold. e. After 15 to 35 seconds, the reaction will settle down and the self-tapping thimble will

open allowing the molten metal to flow into the molds. Tap time should be observed. f. During the critical three minutes after the portion taps, the rail should not be disturbed

in any way, such as bumping fixtures, rails, ties, etc. g. After 3 minutes, the degradable crucible should be removed with the crucible removal

tool. If using a monolith crucible, the crucible can be turned away from the weld and removed.

h. After removing the crucible, gently remove the slag pans from the mold shoes using an

approved tool. .10 Post Heating

When the rail temperature is below 50°F or when drastic climatic changes occur (sudden rain, snow, cold front, etc.), post heating is required. In order to accomplish this, after the crucible taps, the rail should be heated approximately three feet on each side of the mold, using the preheat torch. This should be a light heating on the base and head only, not the web, for one to two minutes. This will help maintain heat into the weld for proper solidification.

.11 Procedures for 2014 Moravia 136# IH Rail with high-alloy chemistry

a. General:

Due to the higher alloying of this 2014 Moravia 136# Intermediate (IH) rail, NS has experienced a higher level of untempered martensite in all welds made with conventional practices while Thermite Welding, Flash-butt welding, and plant welds made at the FAB plant. Since a slower cooling rate is required when welding this rail, a


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new procedure has been adopted to outline how this rail should be welded and managed for optimal results.

2014 Moravia Rail has been installed in the following locations: Dearborn Division

Vermillion – CD 219.3 – 223.0 Track 1 (23 strands, at west end of rail job)

Swanton – CD 297.3 – 311.4 Track 2 (49 strands)

Swanton Yard (72 strands)

Kendallville – CD 375.7 – 383.7 Track 1 (50 strands)

Pocahontas Division,

Kenova District, N and NA Lines, 18 curves between Williamson and Portsmouth

b. Heat numbers have been identified and included in Appendix, figure D, for each of the

rail rollings associated with the identified locations above.

c. 2014 Moravia Rail should be welded by qualified flash-butt trucks using the modified welding program where possible. Thermite Welding is permissible for 2014 Moravia rail but post heating is required regardless of rail temperature. In order to accomplish this, after the crucible taps, the rail should be heated approximately three feet on each side of the mold, using the preheat torch. This should be a light heating on the base and head only, not the web, for one to two minutes.

d. When any rail must be plug repaired, the use of other intermediate hardness (IH) rail

should be used rather than utilizing a 2014 Moravia rail plug for welding back within these identified limits. R&T concluded that there was a significant reduction in untempered martensite present in the welds when plugged using another intermediate hardness (IH) rail in contrast to welding identical 2014 Moravia rail together.

e. If any 2014 Moravia rail is removed from the track, this rail should be marked as scrap

before being removed from the identified limits listed in 4.11b(1.). None of this released rail is to be shipped to the FAB plant for reweld or used in any other location.

5. POST THERMITE WELDING .01 After 4 minutes remove the universal clamp and mold shoes.

a. Prior to shearing, push the top of the mold back to check for solidification. Do not shear if metal is still liquid.


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b. Shear off excess metal and mold material after 6.5 minutes with a hydraulic weld shear. c. If no hydraulic weld shear is available, after 6.5 minutes, hot cut the head riser and bend

foot risers toward outside approximately 45 from vertical. Head riser may also be torch cut while still at red heat.

d. Head riser should be sheared or torch cut away from rail ball before breaking off hot

foot riser. Do not beat on the hot foot riser with a sledge hammer as this can cause hot tears. The foot risers can be broken off hot using a pipe over the riser and bending them back and forth perpendicular to the rail until they break off. The foot risers may also be broken off cold with a sledgehammer. Gently knock off excess sand and mold material from the web and base.

.02 The wedges or other device used to align the rail should be left in place until 10 minutes after

the pour or until the weld has cooled below 900° F. .03 Grind the top and sides of the rail ball to contour. A straight edge may be utilized to ensure that

the weld is not over ground. Do not leave any sharp edges. Grind the top of the base evenly where the foot risers were removed until clean metal is reached. Do not grind below contour or bump the welding collar with the grinding stone.

.04 For proper visual inspection of the collar area, use a wire brush wheel to clean away remaining

sand. If no sand pits are present and no fins are present, the collar may be brush ground to clean metal. If light fins are present that can be lightly pried up and broken away with a chisel, this is acceptable. Do not scar the collar with the chisel. If heavy finning that has burned into the rail is present or heavy pitting in the collar is present, the weld must be contour ground.

.05 Care must be taken to avoid excessive pressure during grinding of the weld in order to prevent

overheating of the rail surface. Final grinding passes shall be light and of a polishing nature. A slight crown should be left in the running surface of welds ground hot to assure a flat surface after the weld has cooled. If the rails are slightly mismatched in order to align the web and base, blend the mismatched welded ends with a profile grinder sufficiently for a smooth run-off. Check frequently with a 36-inch straight edge for proper run-off.

.06 Visible Defects, Low Pours, and Welds Cut Too Low

a. Any visible defect extending below the normal contour of the rail requires that the weld be plug repaired.

b. It is the responsibility of any thermite welder producing a weld with a low pour or

cutting a weld too low to immediately notify MW&S Line Maintenance supervisor so that plug-repair can be made.

c. No excessive grinding is allowed to remove a defect. If it is impossible to immediately

plug-repair a defective weld, the same thermite welder that made the weld must grind it to contour and apply joint bars immediately, and handle to have a proper slow order


17 of 20


issued covering the location of the weld. Prompt arrangements for removal of this defective weld from the track must be made.

d. A PAIR OF JOINT BARS IS NOT TOTAL PROTECTION AGAINST A DERAILMENT CAUSING

FAILURE; therefore, a plug-repair is to be performed without delay. .07 Finished Welds

The finished weld shall have a smooth collar and meet weld finishing dimensions as stated below with no pits or fins due to metal run-out at the edges of the mold.

Weld Finish Dimensions

Tolerances

Vertical Offset 0.060 inch max

Horizontal Offset 0.060 Inch Max

Vertical Crown +0.040 to -0.00

The weld area should be ground so that when a 36-inch straight edge is placed along the top surface of the rail with the weld at the midpoint, the maximum distance between the rail head and the point along the entire length of the straight edge shall be less than the tolerances listed above.

.08 Spiking

a. After completing a weld, the rail will be double rail spiked one tie on each side of the weld, where possible. All other spikes will be replaced as they existed prior to welding.

b. All spikes utilized by the thermite welder solely for the purpose of aligning the weld are

to be removed from the ties. .09 Rail Anchoring

All rail is to be re-anchored to conform to the existing rail anchor pattern for that location. Re-anchoring is to be done immediately after the weld is made.

.10 Clean Up

All scrap thermite material and weld debris is to be removed from the work location by welding gangs. Welding gangs should stock pile released joint bars and scrap track


18 of 20


material at crossings or convenient locations clear of ballast line and walkway for Line Maintenance pickup.

6. RESPONSIBILITY FOR QUALITY THERMITE WELDING .01 No changes in the process or attempted short cuts are permitted. .02 Each thermite welder is responsible for weld quality. After ultrasonic testing of the weld, the

individual performing the test assumes responsibility for weld quality. .03 If inspection determines that a thermite weld is unacceptable, it must be quickly plug repaired.

If immediate repairs cannot be made, the track must be left safe by the application of wrap around bars and a slow order, which are TEMPORARY measures only.

.04 All failed welds, as noted in paragraph 2.08b of this procedure, are to be shipped to the

Research and Tests Laboratory in Roanoke, Virginia, informing them of the shipping receipt number.

7. TESTING THERMITE WELDS WITH ULTRASONIC TESTERS .01 Ultrasonic hand test scope Models USN50, USN52, USM32, and USM35 are authorized for the

ultrasonic testing of thermite welds. These testers are to be used in conjunction with approved 45°, 70°, and 0° ultrasonic test probes after the weld has cooled below 150°F (66°C).

.02 Initial Set-Up of Ultrasonic Testers

Initial set-up of controls must be as directed by a manager welding or Research and Tests Department, and appropriate manuals.

.03 Set-Up of Zero Delay and Gain Controls

For the following test set-ups, zero delay (initial pulse) signal should be just visible on the left side of the test screen. Initial scope set up, including gain and distance for each probe are done with an IIW block. Slight gain adjustments can be made in the field if necessary.

.04 70° Search Probe

a. Set this probe up across the base (6-inch distance). Set the gain so the reflector from the opposite side of the base reaches 80-100% full screen height (FSH). The test screen should represent a 10-inch distance.

b. Make sufficient passes in each direction along the gage, center, and field side of the

weld head to verify that the ball of the rail is defect free. These passes are to be made with a scanning or oscillating motion.


19 of 20



a. Set this probe up on a bolt hole (4.5-inch distance). Set the gain so the reflector from the bolt hole reaches 80-100% full screen height (FSH). The test screen should represent a 12-inch distance.

b. Make sufficient passes in each direction along the gage, center and field side of the weld

head to verify that the ball of the rail is defect free. Passes along the center of the rail head will test down to the bottom of the weld. These passes are to be made with a scanning or oscillating motion.

c. Make sufficient passes of a scanning nature across the base of the rail to ensure that the

center of the base is defect free.


a. Set this probe up on the top center of the rail head (7-inch distance). Set the gain such that the reflector from the bottom of the base reaches 80-100% full screen height (FSH). The test screen should represent a 10-inch distance.

b. The 0° search probe can also be utilized on the top or side of the rail head to search for

defects. c. Make sufficient passes in each direction across the rail surface along the gage, center

and field side of the weld head to verify that the ball of the rail is defect free. Scan back and forth along the side of the rail head if possible.

.07 Testing Guidelines

a. An approved commercial coupling or light oil shall be used in order to ensure proper coupling.

b. Couplant between transducers and angle beam wedges must be checked daily to ensure

proper sound transfer into the weld. c. Instrument set-up must be reviewed by the ultrasonic tester operator several times

during use to determine if the system is testing properly. If the instrument is not operating properly, have it repaired or replaced and retest all welds checked since the last satisfactory calibration.

d. If the ultrasonic test equipment is not functioning properly as shown by a field

calibration over a test block or rail component, the unit should be immediately exchanged for a working instrument or repaired by authorized persons. All welds ultrasonically tested since last normal field calibration are to be retested with a working instrument.


20 of 20


e. Laboratory calibrate ultrasonic testers to standards once every two years and after

repairs on items which would affect calibration. All probes and cables are to be periodically examined and evaluated by the manager welding or his representative.

f. All welding crews must keep accurate records to assure that every weld is properly

ground and ultrasonically tested and is properly reported on the correct form. .08 Care of Ultrasonic Tester Batteries

a. Ultrasonic tester batteries are to be charged and maintained as directed by manufactures instructions.

b. No attempt is to be made to recharge standard or alkaline batteries. c. Different battery types are not to be mixed.

8. REPORTING – Daily Thermite Welding Report (Figure B) .01 This report must be prepared on a daily basis for each day that thermite welding is performed. .02 All required information must be entered in the spaces provided. When working in joint

facilities, the appropriate JF number MUST be entered along with the other required information.

.03 Thermite welders are to note the locations requiring tie re-spacing on the report. .04 The report must be signed by all the appropriate individuals as indicated on the form. .05 Distributions must be made weekly as outlined at the bottom left hand corner of the form. .06 When thermite welding in (1) yard tracks or leads with speeds greater than 25 mph, (2) main

tracks, or (3) sidings and the rail temperature is 75° or less, thermite welders are to determine the amount of rail added (+) or removed (-) when making thermite welds and this information is to be included with the daily thermite welding call-in report.

.07 Any rail added or removed must be entered in inches on the electronic rail added report.

APPROVED by the Assistant Vice President – MW&S

MW&S STANDARD

PROCEDURE 425 THERMITE WELDING


Figure A

MW&S STANDARD


Figure A (cont.)


MW&S STANDARD


Figure B


MW&S STANDARD


Figure C

2014 MORAVIA RAIL IDENTIFICATION:

This rail is from Moravia Steel in the Czech Republic, designated by “TZ” and the symbol preceding it in the brand as shown in the photo below. The picture below indicates a rail heat number that would be considered part of the 2014 Moravia Rail if the heat number and roll date matches any of the listed in Figure D.


MW&S STANDARD


Figure D

Heat Number Date Rolled57546 July-1359342 October-1311127 February-1411129 February-1411131 February-1411134 February-1411137 February-1411139 February-1411142 February-1411144 February-1411146 February-1411148 February-1411151 February-1411153 February-1411155 February-1411157 February-1411160 February-1411162 February-1411165 February-1411167 February-1411169 February-1411171 February-1411173 February-1411176 February-1411178 February-1411180 February-1411189 February-1411191 February-1411193 February-1411195 February-1411196 February-1411197 February-1411198 February-1411199 February-1411201 February-1411183 April-1411184 April-1411185 April-1411187 April-1411188 April-14


MW&S STANDARD


Figure E

2014 MORAVIA RAIL LOCATIONS:

Begin

Date End Date Div District Station ST Pre

M.P.

From M.P. To Suf Trk No

Total

Miles Wgt. Stand Prem Relay

Job

Code

9-Jun 12-Jun DB CHICAGO LINE Kendallville (S-12) IN CD 375.7 383.7 1 8.18 136 86400 0 0 C0012

16-Jun 26-Jun DB CHICAGO LINE Swanton (S-12) OH CD 297.3 311.4 2 14.18 136 149760 0 0 C0013

30-Jun 2-Jul DB CHICAGO LINE Vermillion (TS-24, S-12) OH CD 215.7 223 1 7.09 136 74880 0 0 C0014

29.45

2014 Dual Rail - 2014 Moravia IH Rail Locations

Abbr

eviat

ion Trk L/ Hi/Lo Dir / Wt. Date Amt Job

Gang Start End Div District Station ST Pre

MP

From

MP

To Suf No. R Both Side Rail Top Stand Prem Relay Unld Unld Code

r-1 6-May 7-May PO POCAHONTAS Williamson WV N 469.4 469.5 1 R H L 136 10 2 912 0 0 16-Apr 912 64J79

r-1 20-May 20-May PO KENOVA Goodman WV N 473.8 473.9 2 R L R 136 9 2 1071 0 0 6-May 760 64J83

r-1 20-May 21-May PO KENOVA Goodman WV N 473.8 473.9 2 R H L 136 9 2 790 0 0 6-May 760 64J82

r-1 21-May 22-May PO KENOVA Borderland WV N 475.0 475.2 2 R H L 136 9 2 1759 0 0 6-May 1560 64J84

r-1 22-May 22-May PO KENOVA Borderland WV N 475.0 475.2 2 R L R 136 9 2 1766 0 0 6-May 1560 64J85

r-1 28-May 29-May PO KENOVA Maher WV N 482.4 482.5 2 L L L 136 10 0 1088 0 0 6-May 1120 64J87

r-1 2-Jun 3-Jun PO KENOVA Naugatuck (Swap)

630 ft remain

WV NA 0.9 1.2 2 R H L 136 3 5 1320 0 0 8-May 1320 64Y29

r-1 3-Jun 5-Jun PO KENOVA Stepptown

(Swap) 876 ft

remain

WV NA 7.5 8.0 1 L H R 136 3 6 2820 0 0 8-May 2820 64Y30

r-1 5-Jun 5-Jun PO KENOVA Cyrus (T&S) WV NA 51.5 51.6 2 L H R 136 10 1 1024 0 0 8-May 1000 64K02

r-1 5-Jun 9-Jun PO KENOVA Neal (T&S) WV NA 55.9 56.1 2 R L R 136 10 0 1685 0 0 8-May 1685 64K03

r-1 9-Jun 10-Jun PO KENOVA Neal (T&S) WV NA 56.9 57.1 2 R H L 136 10 1 2038 0 0 12-May 1984 64K04

r-1 12-Jun 16-Jun PO KENOVA Neal (NA 58.9 = N

567.5) {T&S}

WV NA 56.9 57.1 2 R L R 136 10 1 2018 0 0 12-May 1984 64K05

r-1 16-Jun 17-Jun PO KENOVA South Point OH N 573.1 573.2 1 L L L 136 9 1 1028 0 0 12-May 1200 64J88

r-1 17-Jun 17-Jun PO KENOVA South Point OH N 573.5 573.6 1 R L R 136 10 1 846 0 0 12-May 780 64J89

r-1 17-Jun 18-Jun PO KENOVA Coal Grove OH N 575.1 575.2 1 R L R 136 9 1 572 0 0 12-May 575 64J90

r-1 18-Jun 19-Jun PO KENOVA Coal Grove OH N 575.9 576.0 2 L L L 136 9 0 1200 0 0 12-May 1200 64J91

r-1 19-Jun 19-Jun PO KENOVA Coal Grove OH N 576.3 576.4 1 R L R 136 10 1 1460 0 0 12-May 1460 64J92

r-1 19-Jun 23-Jun PO KENOVA Ironton OH N 583.5 583.7 2 R L R 136 9 0 1875 0 0 12-May 1875 64J93

r-1 23-Jun 25-Jun PO KENOVA Superior River Coal OH N 587.0 587.2 1 R H L 136 10 1 2160 0 0 13-May 2160 64J94

r-1 25-Jun 25-Jun PO KENOVA Wheelersburg OH N 600.5 600.6 2 L L L 136 10 1 721 0 0 13-May 630 64J95

r-1 25-Jun 26-Jun PO KENOVA Sciotoville OH N 601.4 601.5 1 R L R 136 9 1 853 0 0 13-May 1056 64J96

r-1 26-Jun 26-Jun PO KENOVA Sciotoville OH N 601.6 601.7 1 L L L 136 10 1 749 0 0 13-May 550 64J97

r-1 26-Jun 26-Jun PO KENOVA Sciotoville OH N 601.7 601.8 1 R L R 136 9 1 951 0 0 13-May 1056 64J98

2014 Curve Rail - 2014 Moravia IH Rail Locations

2.1

1.6

2

2.7

2.5

1.7

1

1.8

2.7

1.5

0.9

1.8

2.1

0.9

0.9

5.1

8

1.8

2.4

1.8

1.8

Curve Rail Wear Linear Feet

2.4

2.3

Deg. Side

r-1


mw&s standard procedure 425 thermite welding

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