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Phone: 905-686-0560Fax: 905-686-0962

USA Corpo rate OfficeGantrex Inc.-Pittsburgh Office2000 Oxford Dr., Suite 400Bethel Park, PA 15102

Toll Free: 1-800-242-6873Phone: 412-655-1400Fax: 412-655-3814

www.Gantrex.com 

GANTREX TECHNICAL BULLETIN  No.   TB47

Crane Rail Inspection 

There are virtually no North American

standards regarding the inspection and

replacement of rails used for overhead

and gantry cranes, transfer cars and

other types of rail-mounted material

handling equipment other than railroads.

There are gauges, programs, systems

and algorithms to measure rail wear on

railroad rails, but very little of it can be

used on the unique profiles of crane

rails. Private companies may have their

own internal standards, and some crane

manufacturers have paddled out into

this deep water, but perhaps some new

industry consensus standards are

needed on this topic.

Most crane rails are inspected and/or

replaced based on the instinct or

experience of the user. This approach

can lead either to the premature

replacement of rails or major problems

caused by waiting too long to replace a

rail or system. Bad rails can result in

damage to the crane or structure,

increased emergency downtime and

unplanned and excessive costs. Rails

that are replaced before they need to be

is like leaving money on the table.

International Standards

There are some international standards

that address the issue of crane rail

inspection, and these should be

examined for possible use in North

 America.

ISO 9927-1:2009 covers crane

inspections, ISO 8686-1 addresses

crane design principles for loads and

load combinations. Both mention

inspecting rails, but offer little more than

theoretical suggestions based on

limiting crane skew caused by rail wear.

Damaged Crane Rail Splice Joint

For member countries of the European

Union, the broad guidelines known as

the, “Machinery Directive” require that

the “manufacturer shall give the wear

limits of equipment in the maintenance

manual”. Anyone who has been around

cranes and runways knows that one of

the big problems is figuring out who is

the “manufacturer” or responsible party

for any crane component below the

wheels. The international consensus

standards provide little help in

determining how to inspect and when to

replace crane rails.

 At present, there are

no North American

Standards regarding

the inspection and

replacement of rails

used for cranes.

 

GANTREX TECHNICAL BULLETIN No. TB47 Crane Rail Inspect ion PAGE 2 OF 3

 

FRA Study

There is also a 1998 report, published

by the United States Department of

Transportation, via the Federal Railway

 Administration titled, “Estimation of Rail

Wear Limits Based on Rail Strength

Limitations”. This report considers the

fracture strength of rails, but pertains

mostly to heavy railroad rail.

These numbers were derived based on

analytical tests conducted on heavy rail

sections that are typically used as

railroad rails. The summary of this 1998

document concludes that rail should be

replaced after an allowable wear of 0.5

inches of head loss or 0.6 inches of face

loss. The entire report can be viewed at

the following government web site:

www.fra.dot.gov .

Whiting Crane Handbook

The Whiting Crane Handbook is a great

resource for information on overhead

and gantry cranes. It also contains

some general guidelines as to runway

maintenance and repair, but offers little

guidance with specific rail issues. All

too often, a rail is not replaced until the

rail sweep or end truck bottoms out, and

these repairs must be done on a costly

emergency basis. 

 AIST Efforts

One group that is currently working on

the issue of rail inspections with two

ongoing projects is the Association for

Iron & Steel Technology, ( AIST). The

Cranes Technology Committee (CTC) of

 AIST  are the producers of Technical

Report #6 for the design of overhead

cranes and Technical Report #13, which

covers mill buildings, including crane

runways. CTC sponsored a recent

survey of crane users to determine rail

 

inspection practices and criteria. The

results of the study confirmed that the

methods of inspection and replacement

criteria are varied by crane user and no

real or replacement criteria exist. The

survey also confirmed that the most

prudent crane users inspect their rails

and runways at least once per year,

along with the crane annual inspection.

Rail splice joints are given particular

attention, since they are often the

source of many rail problems, leading to

damage to the overall rail system and to

the crane itself. Misalignment of the

crane wheels and/or rails will also often

create readily observable problems, but

by this time, it is often too late to repair

any one component and can be solved

only replacing rails or wheels.

The survey also indicated that many

users find information from the Crane

Manufacturers Association of America,

(CMAA) to be helpful in terms of runway

alignment tolerances. (In particular, see

the “Maximum Runway Tolerances”

chart in Specification #70.) The most

significant conclusion derived from the

 AIST survey and research is that there

should be a limit to the amount of rail

wear, after which replacement should be

considered before severe problems

arise.

The follow-on effort to the survey by the

 AIST  committee is the development of

an extensive new technical report with a

working title of “Crane Inspection,

Maintenance and Repair Guidelines”.

The intent of this document is to

describe methods of inspection and

replacement criteria for all aspects of

overhead cranes, and it will include a

significant section on rails and runways.

This new technical report could be

available as early as 2013 from AIST.

 

PAGE 3 of 3  GANTREX TECHNICAL BULLETIN No. TB47  Crane Rail Inspection

 

 Absent any other

replacement criteria,

the 25% rule shou ld

be used as a worst

case scenario.

Rail wear gauge, but

only for railroad rails.

Contact Gantrex at:

1-800-242-6873 or

www.Gantrex.com 

Rail Wear Types

The two most common types of rail

wear are plastic deformation and edge

wear. Each will occur in every crane rail

application, the severity of which

depends on the loading and duty cycle

of a particular runway. Both types of

wear actually displace or remove metal

from the rail surface. The results of this

wear over a long period of time can

weaken the rails to the point that further

damage may occur, leading to failure.

Obvious Signs of Crane Rail Failure

There are several failures of crane rail

that can be easily identified by a visual

inspection of the rail. These include

breaks in the rail, cracks in the rail head

and propagating cracks from splice bolt

holes.

Other obvious signs include the

aforementioned bottoming of rail

sweeps and end trucks caused by

severe wear of the rail over long periods

of use. By the time these conditions are

discovered, the cost and downtime of

emergency repairs is high, and a better

method to determine when a rail should

be changed is needed.

Perhaps the simplest way to determine

the amount of wear on a crane rail is to

measure the dimensions of the rail and

compare them to the dimensions of the

rail when it was new. This can be done

by referencing specification sheets for

the given rail size, or by simply

measuring the rail at a point, such as

the very ends that see little or no crane

travel.

The 25% Rule

One possible method to determine the

amount of allowable rail wear is based

on the wheel load charts found in the

Whiting Crane Handbook. It can be

derived that if a given rail loses 25% of

its overall mass, the rail selection would

drop one complete rail size category,

based solely on the mass of the smaller

rail as it pertains to the wheel load. Said

in another way, if a rail is worn to the

extent that 25% of its mass is has

disappeared, the wheel load would

exceed the amount listed for that rail

size. While this is a basic principle, it

can serve as a ‘lower limit’ of rail fitness

for duty. Actual values may vary, based

on the completion of the research, but

one large crane manufacturer already

uses this criteria when training crane

inspectors regarding rail inspection.

From a practical view, the point at which

a given heavy rail should be replaced is

most likely well before an aggregate

loss of material. According to the FRA

study, a 0.5” loss of head dimension

alone would account for 25% of the rail

mass alone. Absent any obvious

cracking or damage, the 25% rule could

be used as a maximum amount of

allowable rail wear.

Conclusion

Further study to determine more

exacting values of replacement should

be considered by the various technical

committees responsible for crane, railand runway design. END.

  Rev 0 = 4/24/12