united states mtdc portable tdc portable · some systems use high-pressure wands and nozzles...

United StatesDepartment ofAgriculture

Forest Service

Technology &DevelopmentProgram

3400 FHPDecember 20020234-2836-MTDC

MTDC PortableVehicle WasherInterim Report


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The Forest Service, United States Department of Agriculture (USDA), has developed thisinformation for the guidance of its employees, its contractors, and its cooperating Federal andState agencies, and is not responsible for the interpretation or use of this information by anyoneexcept its own employees. The use of trade, firm, or corporation names in this document is forthe information and convenience of the reader, and does not constitute an endorsement by theDepartment of any product or service to the exclusion of others that may be suitable.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs andactivities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs,sexual orientation, or marital or family status. (Not all prohibited bases apply to all programs.)Persons with disabilities who require alternative means for communication of programinformation (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at(202) 720-2600 (voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W,Whitten Building, 1400 Independence Avenue, SW, Washington, D.C. 20250–9410, or call(202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer.

Andy TrentProject Leader

Dick KarskyProgram Leader

Scott GilmourMechanical Engineering Technician

USDA Forest ServiceTechnology and Development ProgramMissoula, MT

1E12D75—Power Washer

December 2002



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Introduction ____________________________________ 1

The MTDC Portable Vehicle Washer _____________ 2Wands and Underbody Washer ________________________________ 2Containment Mat ___________________________________________ 3Holding Tank and High-Pressure Pump__________________________ 4Sump Pumps and Settling Tanks _______________________________ 4Filter Housings and Filters ____________________________________ 5Electrical Power ____________________________________________ 5Mat Reel _________________________________________________ 5

Initial Field Testing _____________________________ 7Results___________________________________________________ 7Filter Analysis _____________________________________________ 7

Recommendations ______________________________ 8

Contents

1

Introduction

Portable vehicle-washer components.

NN oxious weeds, invasive plants, andharmful fungi pose an increasingthreat to native ecosystems, crop-

lands, and other plant communitiesthroughout the United States. While weedshave long been recognized as a problemfor agriculture, their potential impact toother plant communities, including thosein forests and wildlands, is receivinggreater attention.

An estimated 2,000 invasive and noxiousweed species are already establishedin the United States. All ecosystems arevulnerable to invasion, even those thatare largely undisturbed.

On Federal lands in the Western UnitedStates, weeds occur on an estimated 17million acres, with similar infestationsoccurring in Canada and Mexico. OnNational Forest System lands, an esti-mated 6 to 7 million acres are infestedwith noxious weeds. The rate of infestationis potentially increasing from 8 to 12percent per year.

Land managers may use several methodsto control noxious and invasive plants.These methods include chemical spray-ing, hand picking, and biological control.Prevention measures can help keep nox-ious and invasive plants from becomingestablished. For example, many Stateshave implemented programs for certifyingweed-free hay and straw for pack animals.

One prevention measure is to washvehicles before they enter a weed-freearea or when they leave an infested area.Weed seed and fungal spores can betransported in the mud or dirt on vehicles.This is especially true for firefightingvehicles that can be deployed on firesthroughout the country and can transportseed to remote locations. Several ForestService ranger districts and some con-tractors have assembled vehicle-washing

systems to prevent the spread of weeds.Some systems use high-pressure wandsand nozzles (similar to those in a stan-dard car wash) to wash the vehicles. Othersystems use underbody spray systems toremove the dirt and mud from the under-body of the vehicles. These systems uselarge amounts of water because the washwater is not recycled.

The Missoula Technology and Develop-ment Center (MTDC) was asked to designa portable vehicle-washing system to:

❏ Wash a vehicle to remove dirt and muddeposits on the exterior (top and bottom)of the vehicle in 5 minutes. The emphasisof the cleaning should be in the wheels,wheel wells, bumpers, and undercarriageof the vehicle where most mud and dirtcollects. The washing needs to be donequickly so it does not slow down firefight-ing and other operations.

❏ Fit on a single trailer that can be towedby a 3⁄4-ton pickup truck. The systemshould be small enough to be easily trans-ported and should not take up a lot ofspace when it is deployed.

❏ Reuse wash water. This requirementshould eliminate the need to constantlyfill holding tanks or have a water supplyat the washing site. Also, spores andseed can be filtered from the wash waterfor proper disposal.

❏ Be easily operated by no more thantwo persons with minimal training.

❏ Be inexpensive to produce. Low pro-duction costs will allow forests, districts,and private contractors to purchase them.

❏ Wash vehicles ranging from lowboytrailers to all-terrain vehicles (ATVs).

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Figure 1—The MTDC prototype vehicle washer is used to wash a fire engine on the BitterrootNational Forest.

Figure 2—The hand-operated, high-pressure wands are used to thoroughly clean a vehicle’swheel wells, tires, sides, and bumpers where mud, dirt, spores, and weed seeds can collect.

The MTDC Portable Vehicle Washer

TT he center has designed and fabri-cated a prototype portable vehiclewasher to meet the project’s goals

(figure 1). Operators use two high-pres-sure wands to wash the vehicle’s sides,wheels, and wheel wells. An oscillating,high-pressure, underbody washer washesthe vehicle’s undercarriage. An industrialrubber mat with foam-filled barriers onall sides confines the wash water. Theused wash water is pumped from the matto two 175-gallon settling tanks. Largeparticulate matter will sink to the bottomof the tanks. The effluent from the settlingtanks is pumped through two filters. Thefilters have felt bags that can remove par-ticulate as small as 3 microns. After thewater has passed through the filters, itis dumped into a 350-gallon holding tankwhere a high-pressure (about 800 to 1,000pounds per square inch), high-volume(about 20 gallons per minute) pumppushes the water through the wands andunderbody washer. The system does notuse hot water nor does it use any soaps,chemicals, or detergents. The wholesystem is mounted on a double-axle, 8-by 16-foot trailer that can be towed by a3⁄4-ton pickup truck.

The pumps, generator, and tanks arepermanently mounted on the trailer. Thetrailer also carries the mat, hoses, andmiscellaneous equipment.

Wands and UnderbodyWasher

The MTDC portable vehicle washer usestwo hand wands and an oscillating under-body washer. The two hand wands operateat a pressure of 800 pounds per squareinch and spray about 8 gallons of waterper minute (figure 2). Each wand has arotating nozzle that does a better job ofcleaning than standard fan nozzles.

The underbody washer (figure 3) is oneof the few components of the vehicle-washing system that is not commercially

available. The washer uses two pipesmounted parallel with three high-pressurenozzles attached to each pipe at differentangles, one vertical, one 30 degrees leftof vertical, and the other 30 degrees rightof vertical. The pipes are rotated 26 de-grees to either side of top-dead-center by

a series of lever arms driven by an elec-tric motor, a flexible drive shaft, and agearbox. A generator located on the trailerpowers the electric motor. A speed con-troller on the trailer controls the speed atwhich the underbody washer oscillates.The six nozzles operate at about 800

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Figure 3—The underbody washer uses high pressure and a large volume of water to thoroughlywash mud, dirt, and debris from under the vehicle. The nozzles oscillate for complete coverage.

Figure 4—A 19- by 33-foot mat keeps the wash water where it can be recycled. Foam tubes areplaced in slots along the mat’s edges to create a barrier on all sides. The mat shown here wasset up at the Bitterroot National Forest’s Cathedral Fire in August 2002. The wash water drainedto the lower right corner of the mat where a sump pump drew water for filtering and reuse.

pounds per square inch of pressure anduse a total of 18 gallons of water perminute.

During a typical washing operation, avehicle drives slowly onto the mat andover the underbody washer. Once thevehicle has driven completely over theunderbody washer, operators close avalve on the wash system’s trailer, stop-ping the flow of water to the underbodywasher. Operators wash the vehicle withthe two high-pressure wands, removingall mud and dirt on the sides, wheels,wheel wells, and bumpers.

Containment Mat

The containment mat, a Latimat Contain-ment Pad, is distributed by EnvironmentalCleaning Systems, Inc. (figure 4). Therubber mat is 19 feet wide and 331⁄2 feetlong. Cylindrical foam sections are inserted

into sleeves along the sides of the mat,forming raised sides that contain the washwater. A felt liner is placed under the matto protect the mat from cuts or puncturesfrom rocks or other debris. A reel hasbeen fabricated and mounted on the backof the trailer to make it easier to store andset up the mat.

The mat is very durable, but users shouldtake care to ensure that sharp debris isnot underneath it. Rubber-tired vehiclesshould not puncture or rip the mat unlessthe mat is placed over an extremely sharpobject. Industrial conveyor belting shouldbe placed under the tracks of dozers orsmall excavators when they are beingwashed.

Long vehicles, such as school buses, willrequire special handling. Typically, halfof the vehicle is driven on the mat andwashed, then the vehicle is moved towash the other half.

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Figure 5—A 350-gallon tank is the main holding tank for the wash water.

Figure 6—Two cone-bottom tanks are used as settling tanks to remove the larger particulate.The overflow from each tank is pumped through two filters and then to the holding tank.

Holding Tank andHigh-Pressure Pump

Water is stored in a 350-gallon tankmounted on the trailer (figure 5). A high-pressure, high-volume diaphragm pumpsupplies water at a pressure of 800 to1,000 pounds per square inch and a flowof 20 gallons per minute to the underbodywasher and wands. The diaphragm pumpis powered by a 23-horsepower, two-cylinder gasoline engine. A 40-micronstrainer between the tank and the pumpprevents particulate from damaging thepump.

Pressure-relief valves also protect thepump. Between washings, these valvesreduce the pump pressure by routingunused water back to the holding tank.

Sump Pumpsand Settling Tanks

An electrically powered sump pump moveswash water collected on the mat into two175-gallon, cone-bottom settling tanks(figure 6). The water flow from the sumppump is split before the water enters thetanks. Each flow enters the settling tanksthrough large PVC pipes near the bottomof the tanks. The flow is split to minimizethe flow velocities and turbulence, increas-ing the likelihood that particulate willsettle in the tanks.

A 11⁄2-inch hose near the top of each tankdirects overflow water to a smaller holdingtank. Here, a sump pump moves the waterthrough two filters and back to the main350-gallon holding tank. A filter housingand filter bag can be mounted on theoutlet end of the 11⁄2-inch hose to trapdebris such as needles or leaves.

Gate valves and hoses are attached tothe bottom of each of the settling tanksso they can be drained.

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Figure 8—The mat reel is used to manually reel in the mat for transportation and storage

Figure 7—The filter housingsare mounted on the trailer.Cloth or felt filters are used toremove particulate of differentsizes, depending on the user’srequirements. Typically, 20-micron filters will remove mostnoxious weed seeds while 3-micron filters can removeparticles as small as fungalspores.

Filter Housingand Filters

The wash water is pumped through twofilter housings and back to the main hold-ing tank (figure 7). Each filter housinguses felt filter bags rated at 20, 10, 5, or3 microns to remove particulate matteror seeds that are larger than the bag’srating. Any combination of bags can beused, depending on the size of seed orspores that are targeted. A 20-micronfilter bag should catch all seed while thesmaller bags can be used to trap spores.

Each housing is equipped with pressuregauges to determine when the filters areclogging. A pressure differential of 35pounds per square inch indicates that thefilters are becoming full. The filters canbe stored for analysis or removed, back-washed to remove all the debris, andreused.

Electrical Power

A 1,000-watt gasoline generator provideselectrical power to operate the two sumppumps and the motor that drives theoscillating underbody washer.

Mat Reel

A manually operated reel has been fabri-cated to help with the setup, transport,and storage of the mat (figure 8). Thereel is designed so that the mat can beunrolled easily when setting up the wash-ing station. An operator holds one endof the mat down, releases the lockingmechanism, and pulls the trailer forwardover the felt underlayment. Once the matis in place, it can be unfolded for use.

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For storage, the mat should be thoroughlywashed to remove any rocks and debris,dried as thoroughly as possible, andfolded to a width of 46 inches. The frontend of the mat can be lifted, locked into

the reel, and reeled in. A locking mecha-nism prevents the reel from unwinding.Tie-downs and straps hold the mat inplace.

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Initial Field Testing

Figure 9—Filters collect noxious weed seeds and other debris from the wash water.

FF rom August 6 through 9, 2002, theprototype vehicle washer was set upand operated at the Cathedral Fire

camp near Darby, MT. The vehicle washerwas set up at the Deer Creek trailheadabout 11⁄2 miles from the fire camp on theBitterroot National Forest. A contractvehicle-washing system was also set upand operating nearby.

The vehicle-washing system was set upon a level spot at the trailhead. All theused water ran down to one corner of thebarrier and was pumped into the settlingtanks (figure 4). The one drawback of thelocation was that vehicles could not drivethrough the washing station. Instead,they had to drive forward onto the matand back out. This presented problemswhen other vehicles were lined up andhad not left enough room for the vehiclesbeing washed to turn around and leave.

The camp philosophy was that all vehicleswould be washed before entering theforest on the first day. Vehicles were notwashed afterward so long as they weretraveling between the fire and fire camp.All vehicles were to be washed beforeleaving camp during the fire camp’sdemobilization. The intent was to washvehicles during the fire’s demobilization,from August 7 to 9.

A total of 74 vehicles were washed. Thevehicles included cars, pickup trucks, sportutility vehicles, hotshot crew vehicles, fireengines, and a school bus. The wash-water supply tank had to be refilled threetimes (about 175 gallons per refill).

Results

The washing system did an excellent job.It took about 2 to 3 minutes to wash astandard pickup truck, sport utility vehicle,or car. Hotshot crew vehicles, fire engines,or tankers took about a minute or so

longer. The contractor needed about 10minutes per vehicle to wash them. Thecontractor had a very-high-pressure wash-ing system (3,000 pounds per squareinch) that used hot water. He had nocontainment system. All the used waterand debris was left at the site.

The MTDC undercarriage washer did anexcellent job, as evidenced by the amountof dirt and muddy water dropping fromthe vehicles.

During the 3 days of use, the water wasnot drained or flushed from the system.Although “dirty” water was being used towash the vehicles, they appeared cleanafter drying and were mud free. Afterreturning to the center, we found that thesettling tanks had a lot of sediment in thebottom and it was difficult to drain them.It is recommended that tanks be partiallydrained daily to remove sediment, prefer-ably early in the morning after the sedi-ment has settled overnight.

Filter Analysis

The filters used on the last day of testingwere kept for analysis. About 40 vehicleswere washed that day. The filters werebackflushed with water to remove all theparticulate, seeds, and debris that hadcollected on them (figure 9). This materialwas sent to the Montana State SeedTesting Laboratory in the Department ofPlant Sciences at Montana State Univer-sity, Bozeman, MT.

The laboratory’s results indicated thatthe following seeds were collected inthe 20-micron filter:

• Bluebunch wheatgrass (Pseudoroeg-neria spicata)

• Bluegrass (Poa spp.)• Crested Wheatgrass (Agropyron spp.)• Orchardgrass (Dactylis glomerata)• Reed Canarygrass (Phalaris arundi-

cacea)• Sedge (Carex athrostachya)

No seeds were found in the 5-micron filter.

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Figure 10—The sump pump that drewwater from the mat clogged periodicallywith debris such as pine needles, twigs,and grass. A filter sock was fabricated toprevent debris from entering the sumppump.

Recommendations

TT he initial testing of the vehiclewasher proved that the overallconcept of the prototype washer

was sound. Vehicles were washed inabout 2 to 3 minutes, depending on thevehicle’s size and the amount of dirt onit. The undercarriage washer did a goodjob. All of the mechanical components(pumps, tanks, nozzles, and generators)performed as planned. The filters collectedseeds of various sizes and species.

Some items need to be addressed beforethe design of the vehicle-washing systemis completed.

Undercarriage Washer—The system’slocation at the test site required vehiclesto drive over the undercarriage washertwice—once when driving onto and oncewhen backing off of the mat. Two washingsappeared to do a good job in removingdirt and debris underneath a vehicle.Ideally, the mat would be located wherevehicles could “drive through.” This wouldallow only one undercarriage washing,which may not be enough for a thoroughcleaning. To address this issue, a secondundercarriage washer could be placedon the opposite end of the mat to ensurethat the underside would be washed twice.

The overall effectiveness of the under-carriage sprayer needs to be addressed.MTDC is developing a method to deter-mine whether the undercarriage sprayeris providing complete coverage andwhether the sprayer is effective in theareas it covers. One method could involvecovering the bottom of a vehicle with afluorescent dye and then driving thevehicle over the undercarriage washer.Photographs of the vehicle’s undercar-riage could be taken using a fluorescentlight to show the location of any remainingdye.

The center is also investigating usingwater from the high-pressure pump ratherthan an electrical motor to drive the oscil-lating mechanism for the underbodywasher. This change would eliminate theneed for the electrical motor, flex shaft,and motor control, reducing the cost.

Sump Pumps—The sump pump usedto pump the water from the mat cloggedoccasionally because of pine needlesand other debris. To solve this problem,MTDC designed and fabricated a filtersock to be slipped over the sump pump,keeping any large debris from enteringthe pump (figure 10).

Ramp—A small piece of 2- by 6-inchsteel channel was used to protect thehoses and flexible drive shaft whenvehicles drove onto the mat. A piece ofconveyor belting was placed over thechannel to make it easier for vehicles todrive over it. However, a more permanentsolution should be developed and fabri-cated before the next test.

Petroleum Products—Small amountsof petroleum products may come offvehicles during washing. Oil-absorbentpads may be placed in the settling tankoverflow barrel to collect all petroleumproducts as they float to the surface. Thepads can then be disposed of accordingto local regulations.

Drawings and Operator’s Manual—Fabrication drawings and equipment spe-cifications will be developed soon afterthe system’s design is final. These mater-ials will allow districts and contractors tobuild their own washers. An operator’smanual will be developed that addressessetup, operations, maintenance, andcleanup.

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Notes

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Notes

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Andy Trent is a project engineer atMTDC. He received his bachelor’s degreein mechanical engineering from MontanaState University in 1989. Before comingto MTDC in 1996, Andy worked as acivilian engineer for the Department ofthe Navy. Andy works on projects in thenurseries and reforestation, forest healthprotection, and watershed, soil, and airprograms.

About the AuthorsDick Karsky has been program leaderof forest health protection since the fallof 1999. Dick has been a project leaderat MTDC in the resource areas of GPS,range, cooperative forestry, engineering,fire, reforestation and nurseries, residues,recreation, and forest health protection.He obtained a bachelor’s degree in agri-cultural engineering from North DakotaState University and a master’s degreein agricultural engineering from the Univer-sity of Minnesota. He worked for privateindustry before coming to the MTDC in1977.

Scott Gilmour has been a mechanicalengineering technician in MTDC’s shopsince 2001. Scott worked as a submarinetender for the Navy on nuclear subs inthe San Diego area and as a machinistfor the aerospace industry in Utah beforereturning to Montana in 1992 to work onmechanized logging equipment.

Additional single copies of this doc-ument may be ordered from:

USDA Forest Service, MTDC5785 Hwy. 10 WestMissoula, MT 59808–9361Phone: 406–329–3978Fax: 406–329–3719E-mail: [email protected]

Trent, Andy; Karsky, Dick; Gilmour, Scott.2002. MTDC portable vehicle washer:interim report. Tech. Rep. 0234–2836–MTDC. Missoula, MT: U.S. Departmentof Agriculture, Forest Service, MissoulaTechnology and Development Center.10 p.

Describes a prototype vehicle washerthat is mounted on a flatbed trailer andcan be towed by a 3⁄4-ton pickup truck.The washer is designed to be used at firecamps where weed seeds need to be

Library Cardremoved from the underbody and bodyof vehicles before and after the vehiclesleave the area. Operators use two high-pressure wands to wash the vehicle’ssides, wheels, and wheel wells. Thevehicle’s underbody is washed when thevehicle drives over an oscillating, high-pressure, underbody washer. An industrialrubber mat with foam-filled barriers on allsides confines the wash water, which isfiltered before being reused. The prototypewasher was tested from August 6 to 9

when a fire camp was being demobilizednear Darby, MT. It took 2 to 3 minutes towash a standard pickup truck, sport utilityvehicle, or car. It took another minute orso to wash hotshot crew vehicles, fireengines, and a school bus. The washwater supply tank had to be refilled threetimes (about 175 gallons per refill) towash 74 vehicles.

Keywords: fire camps, firefighting, wash-ing, weed control, weeds

Electronic copies of MTDC’s docu-ments are available on the ForestService’s FSWeb Intranet at:

http://fsweb.mtdc.wo.fs.fed.us

For further technical information,contact Andy Trent at MTDC.

Phone: 406–329–3912Fax: 406–329–3719E-mail: [email protected]

united states mtdc portable tdc portable · some systems use high-pressure wands and nozzles...

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