Boston, MA, two window washers fallto their deaths. Preliminary investigationsindicate improper anchorage of their tem-porary suspended platform lines and lifesafety lines to rooftop equipment.Newark, NJ, a waterproofing contractorfalls to his death while moving suspendedscaffolding from one location to another.He had temporarily unhooked his fall pro-tection device to accomplish the move.Minneapolis, MN, a worker was killedwhen his permanently anchored suspend-ed platform failed at one end. He hadfailed to tie his fall protection line to theappropriate anchorage at the roof. Hispartner in the platform is seriously injured,as he tied his harness to the scaffolding. Inall cases, even though the deceased wasfound during investigation of the accidentto have substantially contributed to theirown deaths, the building managers andowners were sued by family members andeither settled or lost each case. In all cases,the building managers and owners werecited by OSHA as not being in compliancewith the regulations. Why were the build-

ing managers and ownerstargeted? Because they didnot have the proper planand certifications for oper-ating suspended platformsfrom their buildings.

Primary regulationsconcerning suspended plat-forms are contained inOSHA Standards 24CFR1910.28 cover-ing suspended platforms, 29CFR1910.66covering personal fall protection stan-dards, and the American NationalStandards Institute (ANSI) and theInternational Window CleaningAssociation’s I-12.1-2001 “WindowCleaning Safety.” Specific jurisdictionssuch as the States of Washington andCalifornia and the City of New York haveadditional, more stringent requirements.These documents represent the minimumstandard of care for building managementand ownership, and serve as guides forbuilding management and ownership. Tosummarize the documents:

1. All devices used to secure, tie, anchor,or support equipment or personnel uti-lized to access building facades 48-inches or more above the level beloware covered by the standards.

2. For all buildings that require personnelto access building façades via equipmentsuspended from roof/balcony levels, per-manent fall protection anchorages mustbe provided by the building.

3. All devices permanently dedicated tothe building shall be maintained by theOwner and shall be designed and cer-tified for use by a licensed profession-al engineer, inspected annually by aqualified person, and inspected prior toeach use by a qualified person.

4. All devices temporarily used on abuilding by a vendor must also bedesigned, tested, and certified by qual-ified personnel prior to use.

5. The owner of the equipment shallmaintain a record of each certificationand annual inspection.

Facility FactsSuspended Platforms –A Complete Plan is Critical

Sometimes the history of an areacan have profound effects on devel-opment. Recently, FEA performedgeotechnical exploration studies fora proposed residential development

along the James River in Richmond,Virginia. The Richmond area was animportant coal producing area fromthe late 1700’s through the early

Geophysical Tools forInvestigating Old Mine Sites

Washington, DC • Houston, TX • San Diego, CA • Denver, CO • Greenville, SC • Seattle, WA

877-322-4589 voice • 703-591-4857 fax • www.feapc.com

FACILITY ENGINEERING ASSOCIATES INFORMATIONAL NEWSLETTERSummer 2003

Volume 11 Number 3

Continued on page 2

Continued on page 3

By Jim Justus, P.E. and Les ZumBrunnen, P.E.

By Paul G. Swanson, P.E.

Suspended weight with dynamometer scaleto load test davit arm

6. The owner of the equipment shallmaintain records of the use of theequipment.

7. The building shall provide to all userswritten procedures for the operation,safe use, and inspection requirementsfor all systems provided by the building.

8. Prior to the performance of work, thecontractor shall develop and provideto the Owner, a Plan of Service for thebuilding that outlines how the con-tractor intends on accessing the build-ing façade, including any movesrequired by the equipment.How do these rules affect a building

manager/owner? They stipulate that per-manent fall protection anchorages mustbe provided on the building, permanentsystems must be load tested and certified,and that a Plan of Service must be devel-oped and maintained for the building.

Currently, a large percentage of thelow- to mid-rise buildings found in theUnited States do not have designated fallprotection anchorages. Both the ANSIand OSHA standards require the retrofitof buildings to provide designated fallprotection anchorages, capable of sup-porting a minimum of 5,000 pounds perattached employee. In many cases, other

structural elements are present on the roofthat can be designated as a fall protec-tion anchorage with the assistance of astructural engineer. However, a singleanchorage cannot be used at the sametime as both a primary support for a sus-pended platform and as a fall protectionanchorage. If the suspended platform lineis anchored to a davit on the roof, thebase of the davit cannot be used to anchorthe life safety line for any individual onthe platform. The intent of this require-ment is to ensure that a failure of ananchorage or line does not result in a fail-ure of both means of support, and subse-quent injury or death.

As part of the building manager/owner’sresponsibility, all permanent system com-ponents are required to be load-tested andcertified at least once every ten years underthe direction of a registered engineer.Further, both periodic and annual systeminspections are required to be completed byqualified personnel. The records of thesecertifications and inspections serve to pro-tect the building manager/owner as theydocument that the systems provided by thebuilding are structurally, mechanically, andelectrically sound prior to the use of thesystems by personnel.

The Plan of Service is intended toadhere to all these guidelines. As outlinedin the ANSI standard, the “Plan ofService” is intended to be a well-thoughtout document that outlines how the con-tractor plans on using the existing perma-nent systems, what temporary systemswill be brought to the site, contractorinspection and emergency procedures, fallprotection locations, identification of haz-ards for both employees and the public, aswell as other important, site specificrequirements. The plan can be preparedby the window-cleaning firm, consultant,or engineer and approved by the buildingmanager/owner.

By providing adequate, certified fallprotection anchorages, and developing afull Plan of Service, a building managerand owner can ensure they comply withthe minimum standard of care for use ofthese types of systems, and minimize thepotential for costly litigation. FEA hasworked with multiple building managersand owners across the country check-ing buildings for compliance, designingnew/retrofit systems, and load testingand certifying various systems, includingdavits, outrigger arms, tie backs, multi-line systems, and others. We can workwith your existing contractors to certi-fy the systems and develop the Plan ofService. For review, certification, orinspection of your system, or for assis-tance in managing the risks associatedwith suspended platform systems, con-tact Jim Justus at 864-787-3903 orjim.justus@feapc.com or LesZumBrunnen at 303-984-7300 orles.zumbrunnen@feapc.com.

Washington, DC • Houston, TX • San Diego, CA • Denver, CO • Greenville, SC • Seattle, WA

Facility Facts

About Facility Facts

Summer 2003

Suspended Platforms – A Complete Plan is Critical — continued from page 1

Facility Facts is an informational newsletter issued quarterly by FacilityEngineering Associates’ staff to share innovative techniques, case studies,trends and general information on issues important to our clients.

Facility Engineering Associates is a national consulting engineering prac-tice specializing in existing facilities and infrastructure. Our expertise is inthe areas of:

• Condition Assessment

• Facility Management

• Repair, Restoration and Instrumentation

• Geotechnical and Environmental Engineering Services

These articles are for general information only, and may not fit yourspecific situation. If you would like to reprint an article or would likemore information about a specific challenge you face, please call:

Jennifer Handy11001 Lee Highway, Suite DFairfax, VA 22030703-591-4855newsletter@feapc.com www.feapc.com

2

Load test of davit and tie back on roofwith dynamometer scale

1900’s. Surface and subsurface coalmines were developed primarily byhand often with slave labor. Themine sites involved large areas andcould extend hundreds of feetbelow the ground surface.Documentation of the mining activ-ities is scattered and often moreanecdotal than factual.

Surface features that evidenceprevious mining activities includemounds of coal waste, rock, soil,and rubble presumed to be spoilsdiscarded during the miningprocess. There are also isolateddepressions at the ground surface.These are “cone-like” depressions,that vary in size and depth, and arescattered throughout the miningarea. These pits can be 20 to 40 feetin diameter and as much as 20 feetdeep. Because of their age, thesefeatures can support large trees andblend into the natural features ofthe forest.

Associated with these surfacefeatures is the potential for settle-ment of the ground surface due tocollapse of subsurface mine shafts.Agencies such as the Bureau ofMine Reclamation have developedstandard practices for the reclama-tion of surface mine features suchas these abandoned mine pits.

However, the investigative toolsavailable for determining the pres-ence or absence of subsurface fea-tures is still limited.

The standard investigativeapproach has been soil boringsdrilled at sufficient frequency toassure the stability of the area sup-porting structures. The subsurfaceinformation obtained from the bor-ings can be correlated with knowngeologic data such as the strike (ori-entation) and dip (inclination) ofthe coal beds. The problem withthis approach is that the cost ofdrilling is high enough to preventadequate coverage of the area to bedeveloped.

FEA recently used resistivitytechniques in combination with soilborings to improve on the delin-eation of mines hidden in the sub-surface. The technique involves themeasurement of the apparent resis-tivity of the earth. An electric cur-rent is applied to the ground viatwo electrodes and the potentialdifference created at the surface ismeasured between two other elec-trodes. The end result is a resistivityprofile along which the change ofresistivity values can be used todetermine what type ofrock/soil/voids occurs at the differ-

ent locations in the ground. Figure2 is an example of the type of crosssection that can be developed fromthis technique. The advantage is amore continuous “look” of the sub-surface conditions, which allowsfor better interpretation across thearea to be developed.

In the case of the residentialdevelopment in Richmond, theresistivity surveys, in conjunctionwith soil borings and geologic mapsof the area, helped delineate areaswithin the development that couldnot be constructed upon withoutfurther study. This allowed thedeveloper to create site plans utiliz-ing areas with severe miningimpacts for green space.Development of the remaining areasof the site will proceed in advanceof further studies and provideincome to defray initial develop-ment costs.

Geophysical evaluations are animportant tool to establish the his-tory of your property in an effort toanticipate potential geotechnicaloccurences, such as significantground settlement. To learn moreabout this project, or about geo-physical evaluations, contact PaulSwanson at 703-591-4855, orswanson@feapc.com.

877-322-4589 voice • 703-591-4857 fax • www.feapc.com

Facility Facts Summer 2003

3

Geophysical Tools for Investigating Old Mine Sites — continued from page 1

Figure 1 -Typical Surface Conditions Around

Abandoned Mine Pit

Figure 2 - Subsurface Profile From Resistivity Survey

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Inside This Issue!

Suspended

Platforms –

A Complete

Plan is Critical

Geophysical

Tools for

Investigating

Old Mine Sites

Facility Facts FACILITY ENGINEERING ASSOCIATES INFORMATIONAL NEWSLETTER Summer 2003

11001 Lee Highway, Suite DFairfax, VA 22030

Volume 11 Number 3

FEA HighlightsJames D. Bakerhas joined FEA in Fairfax, VA as a Staff Engineer inthe Repair and Restoration Group. Mr. Baker has just graduated fromPennsylvania State University’s five-year ABET accredited profession-al degree program in Architectural Engineering.

Christopher B. Wellsand Kevin C. Moultonhave joined FEA inFairfax, VA as Staff Engineers in the Condition Assessment/FacilityManagement Group. Mr. Wells and Mr. Moulton have just receiveddegrees in Facilities Management from Brigham Young University.