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Access to Vehicles


Fall Statistics Related to Workplace Vehicles

Over the last 50 years, accident statistics, including statistics contained in virtually every issue of Accident Facts published by the National Safety Council, indicate that excluding motor vehicle related accidents, the major cause of accidental deaths and serious injuries in the United States is fall type accidents. About 14 thousand people are killed each year as the result of falls, and countless millions are injured.

Falls are a major source of injury in the workplace, and a significant number of these falls are related to falls from workplace related vehicles.

Studies by the Construction Safety Association of Ontario show that 20% of all the lost time injuries in 1978-79 relating to mobile equipment occurred when the operator was mounting or dismounting. (National Safety Council, Construction Newsletter, August 1980)

In a 1980 California study of trucking industry work injuries, the category of "falls" constituted 16.1 % of all injuries. According to the occupation of those injured in falls, 19.9 % occurred to "truck drivers" and 14.0 % occurred to "delivery-men and route-men." According to the source of injury on those injured by falls, 82.0 % were related to "working surfaces." (National Safety Council, Accident Facts, 1982.)

"Truck driving is often considered a dangerous business because of the countless traffic, road, and weather hazards. Yet, more drivers are hurt each year by slipping and falling from non-moving vehicles than by any other single cause." This publication reported that (a) a University of Michigan study on hazards faced by truck and bus operators estimates that slips and falls in and around vehicles account for as much as 25% of all driver injuries, (b) a Liberty Mutual Insurance Company says one in every nine truck driver injuries is a result of a slip or a fall from a non-moving vehicle, and that those injuries account for 15-25 % of all trucking employee injuries, (c) a California Department of Industrial Relations study involving disabling injuries to drivers in and around non-moving trucks and tractors over a six month period showed that 84% involved cab entry or exit, and of those, 88% were slips and falls, (d) an International Brotherhood of Teamsters study indicated that 11.4% of driver accidents involve falls from vehicles, with the only larger accident category involving lifting heavy objects, (e) a Professional Drivers Council for Safety study of motor carrier injuries in New York State revealed that 45% involved slips and falls from stationary vehicles, and that in the group studied such accidents were most likely to occur during loading and unloading operations, and (f) in a Transportation Association of Ontario study, slips and falls in and around motor vehicles accounted for 40% of all slip and fall accidents, with 20% involving trailer hook-up, 28% involving tarpaulins, and 52% involving cab and cargo area ingress and egress. (Duncan, Thomas, assistant editor, Fleet Owner, March 1978)

In a 1974 study (published in 1977) conducted by the Federal Highway Administration's Bureau of Motor Carrier Safety of the State of California statistics related to slip and fall type injuries in the trucking industry, slip and falls accounted for 14% of all driver injury accidents and 9% of all carrier's injury accidents, with 54% of such slip and fall incidents occurring on the tractor or driver area and 46% occurring on the trailer or cargo area. Tank carriers had the highest percentage of driver slips and falls (23%); followed by auto transporters (14%), van-type (11%), and flat bed (9%) (Bureau of Motor Carrier Safety, U.S. Department of Transportation, "Slips and Falls -- Truck Related Personal Injury Accidents," July 1977).

In a special study conducted in 1971 by four motor carriers, at the request of the Federal Highway Administration's Bureau of Motor Carrier Safety, the following information on slips and falls was reported: The total number of driver injuries was 1,667. Of this total (1,667), 334 (20.0%) involved slips and falls, and of these, 55 (16.5%) involved cab entry/egress falls, 31 (9.3%) involved behind tractor coupling/uncoupling falls, and 248 (74.3%) involved loading or cargo related falls. Of the 55 cab entry/egress falls, 13 (23.6%) involved automobile carriers, 3 (5.5%) involved dry bulk carriers, 34 (61.8%) involved general freight carriers, and 5 (9.1%) involved bulk liquid carriers. Of the 31 behind tractor coupling/uncoupling falls, 10 (32.3%) involved automobile carriers and 21 (67.7%) involved general freight carriers. Of the 248 loading or cargo related falls, 110 (44.4%) involved automobile carriers, 135 (54.4%) involved general freight carriers, and 3 (1.2%) involved bulk liquid carriers.

In the factsheet "Falls of Workers" published by the National Safety Council in 1946, it is recognized that "improvement in the accident experience of companies operating fleets of motor vehicles depends considerably on preventing falls... Most falls occur when workers get on or off vehicles. [The]... most numerous injuries are incurred when the vehicles are standing still. [Persons should not be allowed] to work close to the edges of flat bed trucks when loading or unloading them. Falls are especially frequent when truck beds are in bad condition, or when the materials or truck beds are wet, muddy, or icy." (National Safety Council, "Falls of Workers," Safe Practices Pamphlet No. 99, 1932, 1946)

The prevention of vehicle related falls should be a major concern to the designers and administrators of any workplace (or work related) vehicle.


Prevention of Falls Related to Workplace Vehicles

A practical approach to the prevention of vehicle related falls dictates consideration of (1) the physical design characteristics of the vehicle access system (handholds and footholds) and related support features, (2) general fixed user characteristics, (3) characteristics of common shoe sole and heel materials, (4) anticipated environmental conditions, and (5) cleaning, inspection, and maintenance methods and provisions. In the prevention of falls, while each of these items should be taken into account, only items (1) and (5) are generally subject to practical control, with item (1) being subject to the most effective control.


Access to Operating or Work Positions
of Industrial Vehicles and Equipment

The term "access" in relation to industrial vehicles, or the term "access to vehicles" refers to the handholds, footholds, and similarly purposed features that are specifically designed to facilitate climbing to and from various locations on such vehicles and to prevent vehicle related falls.

The task of ascending to and descending from the various surfaces of industrial vehicles and equipment is similar to ascending or descending stairs or ladders, except that the surfaces utilized are often very irregular in location and dimension. Often, the descent from a vehicle or piece of industrial equipment must be performed "backwards," similar to descending an irregular dimensioned ladder.

Due to the generally reduced size of "walking surfaces" utilized to access industrial equipment operator and vehicle maintenance positions, and the typical vertical movement of the body in such situations, it is vital to give special attention to the design of proper handholds and footholds in terms of size, location, orientation, and friction (slip resistance) characteristics, in order to maintain balance and stability during vehicle access and to prevent falls.

The primary principle used in the safe design of vehicle access systems is to allow for the continuous use of a three point attachment system; that is, sufficient and adequate handholds and (slip resistant) footholds to keep at least two feet and one hand, or one foot and two hands, securely "attached" to the vehicle at all times. This necessitates the design of a four point attachment system throughout the access route to allow for one hand or one foot to be in movement to the next handhold or foothold during the vehicle access process.

Without a continuous three point attachment, the body is unstable, easily imbalanced, and susceptible to "swing" forces; that is, an imperfectly balanced one hand and one foot attachment will, for example, act as a "hinge," swinging the body away from the vehicle as the body's center of gravity seeks its balance point (equilibrium). Further, without a three point attachment, any misstep or imperfect grip experienced during use, which must be reasonably anticipated over time, has a high probability of resulting in a fall, as there is either no "backup" handhold or foothold to maintain balance, or one must frantically seek some type of hand or foothold while in the process of falling.

A major standard used in the design of safe vehicle and equipment access systems is SAE J-185 (1970), first published in 1972 under the title "Access Systems for Construction and Industrial Equipment." As human requirements for adequate handholds and footholds are obviously fixed and dictated by the capabilities and limitations of physical and physiological characteristics of the human body in terms of body balance and stability (that is, because humans remain humans whatever it is that they must climb), this standard (regardless of apparently limiting title changes), in terms of technical content, offers comprehensive handhold and foothold design criteria that can be applied to a wide variety of industrial equipment and vehicles. This is also true for the handhold and foothold design criteria published in 49 CFR (DOT) Part 399, Subpart L (circa 1982) titled "Step, Handhold, and Deck Requirements for Commercial Motor Vehicles," which presents requirements for "cab-over-engine" trucks and truck-tractors, but indirectly supplies authoritative technology for any other similar vehicle where such technology can be applied to prevent falls.


Select Requirements of SAE J-185 (1970) --
Access Systems for Construction and Industrial Equipment

SAE J-185 was first published in 1970. This landmark publication set forth basic requirements for the design of adequate handholds and footholds for climbing irregular vertical surfaces such as those encountered when climbing to the operator's cab on various construction and industrial vehicles. Enhancing clarity with minimal changes to its content, this publication was revised in 1981, 1985, and again in 1988.

Select requirements of J-185 (1970) include:

  • Section 4.7 of SAE J-185 (1970) states: Steps, ladders, and grab rails to, on, and from platforms and walkways, should be designed to invite the person using them to have three limbs on the system at all times. (Two hands and one foot, or two feet and one hand.)

  • Section 5.1 of SAE J-185 (1970) states: The maximum height of the first step from the ground to the machine should not exceed 30 inches when the machine is in the normal parked position. The preferred height of this step is 16 inches.

  • Section 5.2 of SAE J-185 (1970) states: The maximum distance between steps of vertical ladders on machines is 16 inches. The preferred distance between steps is 12 inches.

  • Section 5.3 of SAE J-185 (1970) states: Where lateral movement is necessary from the top step of a vertical ladder to a walkway or a platform, the vertical distance should be no more than 12 inches.

  • Section 5.6 of SAE J-185 (1970) states: The minimum toe clearance from the outside edge of the step should be 5 inches. The preferred distance is 7 inches.

  • Section 5.11 of SAE J-185 (1970) states: The design of steps should minimize the accumulation of debris. The tread surface should be a high slip resistant surface and should aid in the cleaning of mud and debris from the shoe sole.

  • Section 6.1 of SAE J-185 (1970) states: Grab rails, appropriately spaced to provide continuous support to a moving man, should be placed within convenient reach.

  • Section 6.2 of SAE J-185 (1970) states: The preferred cross section of a grab rail and grab iron is circular. A square or rectangular cross section with round corners is permissible.

  • Section 6.3 of SAE J-185 (1970) states: For circular cross section grab rails and grab irons, the maximum diameter should be 1-1/2 inches. The minimum diameter should be 3/4 inches. The preferred dimension is 1 inch. For square or rectangular cross section, these dimensions apply across flats.

  • Section 6.6 of SAE J-185 (1970) states: Grab rails and successive grab irons should be placed parallel to the path of motion of the user. Grab irons may be oriented vertically or horizontally but should be consistent within a given system.

  • Section 6.10 of SAE J-185 (1970) states: On incline ladders, where hip clearance is a factor, the preferred spacing between parallel grab rails is 24 inches.

  • Section 6.11 of SAE J-185 (1970) states: The preferred grab rail height vertically above any step or incline ladder is 36 inches.

Select requirements of J-185 (1988) include:

  • Special Note: This recommended practice conforms in all significant detail with the international standard ISO 2867-1980.

  • Purpose. This recommended practice establishes criteria for access systems primarily to aid in minimizing accidents and injury to personnel getting on, off, or moving about while servicing or preparing to operate off-road machines.

  • Section 4.5(f) of SAE J-185 (1988) states that access systems shall: Be obvious as to proper usage without special training.

  • Section 4.5(g) of SAE J-185 (1988) states that access systems shall: Permit and, by proper placement of components, promote achievement of three point support while ascending or descending the access system when more than one meter above the ground.

  • Section 4.7 of SAE J-185 (1988) states: Step, walkway, and platform surfaces (including any machine or tool structural component used as part of an access system) as a minimum shall be slip resistant at the foot contact areas.

  • Section 5.1 of SAE J-185 (1988) states: Steps shall conform with the recommended dimensions in Table 1. It is preferred that all steps be wide enough to accomodate both feet.

  • Select minimum dimensions contained in Table 1:

    • Step width (one foot) 160mm (6.3") 200mm (7.87")
    • Step width (both feet) 320mm (12.6") 400mm (15.75")
    • Toe clearance 150mm (5.9") 190mm (7.87")
  • Section 5.3 of SAE J-185 (1988) states: Steps shall be coordinated with properly positioned handrails and handholds.

  • Section 5.5 of SAE J-185 (1988) states: Step design shall minimize foot slipping laterally off the step.

  • Section 5.8 of SAE J-185 (1988) states: Step design shall provide natural foot placement while descending or the step shall be clearly visible while descending.

  • Section 8.1 of SAE J-185 (1988) states: Handrails and handholds shall conform with the recommended dimensions in Table 2.

  • Select dimensions contained in Table 2:

    • Mimimum Distance above standing surface 900mm (35.43")
    • Maximum Width between parallel handrails 600mm (23.62")
  • Section 8.2 of SAE J-185 (1988) states: Handrails shall be appropriately spaced to provide continuous support to a moving person and within convenient reach.

49 CFR (DOT), Part 399, Subpart L

A sister standard to SAE J-185 is the U.S. Department of Transporation's 49 CFR (DOT), Part 399, Subpart L, promulgated for cab over engine (COE) highway trucks.

Select provisions include:

  • Section 399.205, Definitions, of CFR 49 CFR (DOT) Part 399, Subpart L states that a "handhold" means "that which qualifies as providing full grasp if a person is able to find a hand position on the handhold which allows more than fingertip grasp."

  • Section 399.205, Definitions, of CFR 49 CFR (DOT) Part 399, Subpart L states that a "fingertip grasp" means "a handhold surface which provides a person contact restricted to finger segments 1 and/or 2 only; or which limits wrap-around closure of finger segments 1 with the palm of the hand to 90 degrees" (as illustrated in Illustration I of the printed standard).

  • Section 399.205, Definitions, of CFR 49 CFR (DOT) Part 399, Subpart L states that a "full grasp" means " a handhold surface which provides a person contact with finger segments 2 and 3 and which provides space for finger segment 1 to wrap around toward the palm of the hand beyond [a] 90-degree surface. The handhold need not require contact between fingers and thumb" (as illustrated in Illustration II of the printed standard).

  • Section 399.207 (a), General Rule, regarding truck and truck-tractor access requirements of CFR 49 CFR (DOT) Part 399, Subpart L states: "Any person entering or exiting the cab or accessing the rear portion of a high profile COE truck or truck-tractor shall be afforded sufficient steps and handholds, and/or deck plates to allow the user to have at least 3 limbs in contact with the truck or truck-tractor at any time. This rule applies to intermediate positions as well as transition between intermediate positions. To allow for changes in climbing sequence, the step design shall include, as a minimum, one intermediate step of sufficient size to accommodate two feet."

  • Section 399.207 (b)(3), Performance Requirements -- Construction, regarding truck and truck-tractor access requirements of CFR 49 CFR (DOT) Part 399, Subpart L states: "Each step or deck plate shall be of a slip resistant design which minimizes the accumulation of foreign material. Wherever practicable, a self-cleaning material should be used."

  • Section 399.207 (b)(4), Performance Requirements -- Foot Accommodation, regarding truck and truck-tractor access requirements of CFR 49 CFR (DOT) Part 399, Subpart L states: "Step depth or clearance and step width necessary to accommodate a climbing person are defined by using a minimum 127 millimeter (5 inch) diameter disc..." Further, in (4)(b)(i) regarding single foot accommodation, "the disc shall fit on a tread rung, or in a step recess, with no exterior overhang." Also, in (4)(b)(ii) regarding two-foot accommodation, "two discs shall fit on a tread rung, or in a step recess, with no exterior overhang."

  • Section 399.207 (b)(6), Performance Requirements -- Handhold Location, regarding truck and truck-tractor access requirements of CFR 49 CFR (DOT) Part 399, Subpart L states: "A handhold must be located within the reach of any person entering or exiting the vehicle."

  • Section 399.207 (b)(8), Performance Requirements -- Handhold Shape, regarding truck and truck-tractor access requirements of CFR 49 CFR (DOT) Part 399, Subpart L states: "Each handhold shall be free of sharp edges (minimum 1 millimeter [0.04 inch] radius) and have an effective peripheral grip length that permits full grasp by any person."

  • Section 399.207 (b)(8), Performance Requirements -- Handhold Strength, regarding truck and truck-tractor access requirements of CFR 49 CFR (DOT) Part 399, Subpart L states: "Each handhold shall withstand a horizontal static load of at least 114 kilograms (250 pounds) uniformly distributed over the area of a hand print and applied away from the mounting surface."

  • Section 399.211, Maintenance, regarding truck and truck-tractor access requirements of CFR 49 CFR (DOT) Part 399, Subpart L states: "All steps, handholds, and/or deck plates required by this subpart shall be adequately maintained to serve their intended function."


Website Sources for Truck Fall Protection

The design of vehicle protection systems is rapidly changing as new equipment and means to provide fall protection enters the market on a regular basis. One might start by consulting the following websites, and further searching using the key words associated with truck and vehicle fall protection:

Carbis

CAI Safety

FPS Fall Protection Systems

Spanco


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