Specs for Bucket Entry
Published in: Utility Products
Date: 9/1/2005
By: Michael Hudson
Safety is the key, but there are still many options available to you. We present here a manufacturers point of view.
As anybody who has tried to write an equipment specification knows, there are “gray areas” that are difficult to describe on paper. One of the most perplexing items to specify is the issue of entering and exiting an aerial device bucket. Because of the way the aerial device booms and buckets interact with the truck body, the truck cab, and the electrical accessories (strobes, work lights, radios, etc.), it is not easy to predict where and how everything is going to go together. Sometimes it seems to be a lot easier to get a lineman 60 in the air than it does to get him from the bed of the truck and into the bucket!
Over the years I have had the opportunity of meeting fleet managers, engineers, and specification writers from across the country during inspections of aerials that my company (LIFT-ALL, Division of Hydra-Tech, Inc.) is building for them. Most of the time, these inspections go smoothly, but one issue that persistently comes up is debate over the best way for an operator to enter and exit an aerial device bucket.
In order to gain some perspective on this important topic, kindly allow me to share a few things I have encountered while working with customers on this issue. Please note that I am not trained as a safety engineer or an ergonomics expert. These observations come from over a dozen years working at LIFT-ALL with utility customers and of listening to them discuss their ideas about bucket access during the course of pre-build meetings, equipment inspections and hundreds of phone calls and emails.
Bucket access: What is safe?
For manufacturers building equipment for the utility industry, there are a number of general guidelines to follow to ensure an industry standard for safety. In particular, ANSI and OSHA provide a host of guidelines for design safety factors, dielectric testing and other issues of critical importance to the utility industry. When it comes to accessing the aerial device, however, none of the guidelines are truly specific. As a manufacturer, I believe this lack of specificity is a good thing; because of the bewildering number of aerial device designs available (LIFT-ALL has over 100 different models), it would be impossible to write guidelines that would cover every possibility. By leaving the guidelines “open,” it allows the manufacturer and the fleet purchasing the equipment to work together to arrive at the best solution for each situation.
Bucket access: What is possible?
When it comes to bucket access, the ideal situation is a large, stable platform with a comfortable stepping distance and easily accessible grab handles. The problem with access steps on aerial devices (and digger derricks, cranes and other types of equipment) is the fact that aerials rotate, articulate and/or telescope. Everywhere a part of the aerial can move must remain clear. The units range of motion dictates the size and location of any step installed on the unit. It is because of this that step design is almost never as good as it could be because the equipment itself imposes limitations on the design of the step. In other words, although a 4 long by 2 wide step would be perfect for accessing the bucket, such a step hits the turntable during rotation.
One of the biggest problems I see in discussions about bucket access is keeping everybody happy within a utility fleet. In many cases I see where one access step layout works fine for the crews at garage B, but over in garage A, this same design is seen as unsafe and unacceptable. This creates quite a headache for a Fleet Manager trying to implement a standard fleet-wide design and centralize equipment purchases. It is also a problem for the manufacturer trying to build the unit. One solution is to allow each area, or even each crew, to dictate the design for accessing the bucket. The problem with this is that equipment is not standardized, which causes problems with moving trucks to different areas of the fleet, added expense, delays, etc. From a manufacturing perspective, it is easiest for us to build the same step over and over again, but at LIFT-ALL we are more than willing to accommodate individual designs for each truck if that is what is wanted. Uniformity in a fleet is generally a good thing, but some fleets find it is best to allow each truck to be tailored to individual regions or crews.
What is Unacceptable?
Only once in my years at LIFT-ALL have I ever encountered a customer request for bucket access that I thought was unsafe. This case involved a fairly large investor-owned utility that was allowing each crew to build their truck as they saw fit. In one case, one operator wanted the fiberglass inside/outside bucket step (the one actually built into the fiberglass bucket) to be built into the wall of the bucket facing the outside of the truck. This design would have the lineman suspended over the side of the truck while entering and exiting the bucket. From a manufacturing standpoint, moving the step is not a big deal, but we thought this was a terrible idea, and told the customer so (politely, of course). As for all the other suggestions I have heard over the years, they were all reasonable, valid ideas.
So how do you specify the rights solution? Because of some of the variables discussed above, it is best not to get too specific in designing bucket access. Something specific like “An access ladder 4 tall by 12″ wide installed on streetside compartment top…” might not work the way you think it will. However, there are a few guidelines you can provide for your equipment providers:
1. Specify stepping distance. At LIFT-ALL we try for a 20″ maximum stepping distance (if the customer does not specify anything different). We feel this is a comfortable distance for the average person. But perhaps your fleet has decided on a 16″ maximum stepping distance. No problem! Just note this in your specifications.
2. Specify hand holds: Again it is probably best not to get too precise about the number and nature of grab handles, but a note that the operator must have an easily-accessible point to grab does give the manufacturer something to go by. Some of LIFT-ALLs accounts emphasize a “three-point” system where both feet and at least one hand are in secure contact with the equipment at all times. The exact details are worked out during the design and building process. As I always tell customers during inspections, LIFT-ALL never charges extra for the addition of a grab handle; we stock them by the dozen and can install them in a matter of minutes.
3. Specify that Bucket Access is “To Be Determined”: There is nothing wrong with indicating in an equipment specification that equipment access design will be determined at a pre-build meeting or during inspection. This allows you to have control over the final design, but this design is worked out in conjunction with the manufacturer.
In conclusion, there is no perfect way to access an aerial device bucket. The best thing to remember is that the manufacturer is generally quite flexible in designing bucket access. So long as the fleet manager works closely with the manufacturer to work out the design, bucket access can generally be accomplished safely and easily.