What’s Your Bucket IQ?

I know a lot about buckets, but it wasn’t until after I hung up my tools that I learned much of what I’m going to share with you in this article.

Background
I was lucky to work as a lineman when I did. The buckets we used at Florida Power & Light through the 1970s were unlined, simple fiberglass Hi-Ranger platforms that got us close enough to the wire that we could hot-stick it. In my opinion, the Hi-Rangers of the ’60s and ’70s were the best bucket trucks ever built, and I know I’m not the only one who thinks so.

We didn’t glove at FPL back then, but when we started, I was the newest foreman operating the oldest line truck. Soon I became the first foreman out of the northeast service center to operate the new over-center Asplundh Line-Lift double gloving bucket with a material-handling jib. This technology was brand new to the line industry. FPL’s lift featured an electric-over-hydraulic boom with a large, enclosed, 48-volt battery stack behind the cab that would turn the power takeoff, providing hydraulics for boom and bucket operation. The battery bank charged slowly while the truck’s engine was running, so if you ran the boom on electric, you had to plug it in at night to get any time out of it the next day.

Because the technology was so new, an Asplundh trainer spent a couple days teaching me and my crew how to maintain and use the truck, particularly the material-handling boom. That was when I first learned that fiberglass gloving buckets with insulating liners – like those on my Line-Lift – are not truly insulating. The trainer instructed us not to lift wire with the bucket, even with rubber hose on it. More specifically, we were warned never to let the bucket contact uncovered wire and, when gloving, never to let the bucket contact the pole. The Asplundh training session was also where I learned that, while nonconductive, the hydraulic fluid used in insulating aerial devices is highly flammable, especially when atomized by system pressure through a small puncture in a hydraulic hose.

And now, a brief warning: Should you choose to stop reading here, remember that the rules in the previous paragraph remain true and legally enforceable today.

Insufficient Operator Training
As I’ve noted in the past, I provide litigation support services, offering subject matter expertise on power-line training and operations and OSHA. I’ve worked on several bucket-fire cases over the years, including two I’m currently assisting with, but it was the first bucket-fire case I ever worked on that really caught my attention – most notably due to the clear lack of sufficient training for our industry’s bucket operators. My experience suggests this lack of training persists.

In that first bucket-fire case, a four-man crew had been tasked with transferring a tangent crossarm three-phase primary to make room for a roadway curb pavement expansion. The poles were about 5 feet apart and 2 feet out of line. The #2 copper primary was at the same elevation on the new pole. A lineman was in the material-handling bucket, a six-step apprentice was on the new pole, and the foreman and a first-year helper were on the ground.

The crew was using the material-handling jib, equipped with a wire roller clip attachment, to move the primary. The apprentice, with a jumper-holding hot-stick, helped them successfully transfer the far-side phase. The lineman tied in the phase with crew-fabricated, soft-drawn #6 wire ties.

As the crew transferred the middle phase, everything quickly went wrong. The crossarm was mounted on the bucket side of the pole, and the pole-top pin for the middle phase was mounted on the back of the pole. As the lineman moved in the bucket to land the phase, the corner of its control box contacted the new crossarm. There was no audible sound, according to the crew, but the apprentice and foreman stated that they witnessed smoke coming from the bucket’s control box and called it out. The lineman, who did not have full situational awareness, was partially dropping the wire on the insulator and needed to secure the phase. Trying to do so delayed him from moving the bucket away from the crossarm. Flames erupted around the controls just as the lineman tried to reach in to use them, preventing his attempt.

The foreman called for the apprentice to get down from the pole and then moved the bucket with the lower controls. As he moved it, the half-landed phase went to ground on the pole top, locking out the feeder that was on “one-shot” nonautomatic. Halfway down, the bucket’s hydraulics failed; they had been feeding the fire. The lineman escaped by sliding down the boom and dropping into the truck bed. He had first-degree burns on his face and hands, through his leather gloves, plus a broken leg and collarbone from landing on rolls of triplex and a stack of screw anchors.

This incident confirmed my opinion that the best approach to moving a phase is not tying down a flying bucket with an energized phase. A couple things went wrong, starting with the fiberglass jib. The crew believed it was insulating, so they had added the wire roller clip attachment and then proceeded to land a hot phase on it at the end of the jib. Despite what you may have seen in some pictures and advertisements, the major material-handler manufacturers warn that jib booms and jib winch lines are not intended for use as energized material-handling booms. Insulating links on the jib are intended to hold energized conductors. Use a link between the hot phase and the rope hook, holding energized wire with the material handler’s winch rope.

Did you know that buckets, too, are largely not considered to be insulating? In nearly all instances, the lineworkers I have spoken with during audits had never questioned the insulating value of fiberglass jibs or buckets, which – ironically enough – the industry commonly refers to as “insulating buckets.”

Understanding Primary Insulation
It is important that readers understand how “primary means of protection” is defined. In energized work environments, employers are required to safeguard employees from energized contact. The first – or primary – protective means must be designed for the task and periodically inspected and tested to ensure proper functionality; intervals have been established by consensus standards and are recognized by OSHA. These rules also apply to buckets, but OSHA standards do not call out bucket-boom testing specifications the way they do specs for rubber gloves, sleeves and hot sticks. Instead, the ANSI A92 family of standards establishes maintenance rules for insulating aerial devices that OSHA recognizes and enforces through the General Duty Clause.

Here is what you should know about the Category B insulating gloving buckets referenced in ANSI A92. Their booms and bucket liners, if present, must be tested annually. However, booms and liners are considered secondary means of protection for the worker in the bucket because annual electrical testing without periodic close inspections and maintenance does not ensure employee protection.

Rubber gloves or hot sticks serve as a worker’s primary protective means. Yes, without incident, crews occasionally bump uncovered wire with buckets and frequently land hot conductors with the fiberglass jib. How? The boom insulation keeps buckets isolated from ground. But boom insulation could not protect that lineman who shorted out his bucket against a wet new crossarm and pole. Buckets, jibs, hoses and winch ropes are subject to contamination by road salt and atmospheric conditions. Equivalent salt deposit density testing is used to measure salt contamination on electrical insulators, quantifying soluble salts – like road salt and coastal spray – on the insulators’ surfaces. When damp or wet, they create a conductive film that reduces insulation strength and could cause flashovers. Testing has demonstrated that buckets hung over the backs of trucks are highly susceptible to road salt contamination, as are jib booms. When the bucket contacted the crossarm in the incident described earlier, it tracked over and began arcing to the arm. That ignited the fiberglass and eventually burned a hole in some of the hydraulic lines, adding flammable hydraulic spray to the fire.

Frequent Issues
The remainder of this article focuses on the most frequent bucket truck issues I have discovered during incident investigations and program audits. Relevant ANSI A92 rules – which refer to the trucks as mobile elevating work platforms, or MEWPs – are italicized, and many are followed by my unitalicized commentary.

4.9.4.3 Strength requirement. Anchorages shall be capable of withstanding a static force of 3600 lbs. (16,000N) for each person allowed by the manufacturer on the attachment without reaching ultimate strength. The strength requirement shall apply only to the anchorage(s) and their attachments to the boom, platform, or platform mounting. (ANSI A92.2)

You will notice that the rule states 3,600 pounds, establishing the equipment requirement. Per OSHA and ANSI Z359, a fall arrest anchorage is 5,000 pounds. That means your system must limit restraint forces to the limits of the anchorage. I’ve included more information below regarding self-retracting lifelines, sometimes called SRLs or retractables.

Note to 4.9.4.3: This does not imply that the aerial device is meant to meet or comply with this load requirement. (ANSI A92.2)

Pay attention to this note. It means the anchorage attachment is rated, but the bucket or boom the anchorage is attached to may not be. Using the correct devices, such as retractable and deceleration attachments, limits strain on the boom and bucket mounts.

When it comes to bucket fall protection, most of us are generally satisfied with a full-body harness and a 6-foot lanyard. OSHA’s opinion, however, is that retractable lanyard use is the best way to prevent workers from leaving buckets during ejection events. The small, short personal retractables tend to lock up before workers can exit. But even if someone does go over the side, the SRL will prevent them from hitting the turntable below, which remains a fall protection requirement.

By the way, the first personal retractable was developed in conjunction with an employer after a lineman, ejected from a bucket due to a boom issue, was fatally injured upon striking the truck. OSHA is on record approving a settlement adopting retractable lanyards in at least two struck-surface-below ejection cases that I am aware of.

Another potential benefit of SRLs is that in most ejection scenarios, they have entirely prevented users from leaving their buckets, a critical feature when timely rescue is required after a fall arrest. For lone workers, this nearly eliminates the issue of self-recue from suspended heights.

4.9.4.4 Connector requirement. Anchorage shall be compatible with a lanyard connector complying with ANSI/ASSP Z359.1-2017. (ANSI A92.2)

4.9.4.1 Location. The manufacturer shall provide anchorage(s) on the boom, platform, or platform mounting. The anchorage shall be designed to protect against detrimental interference between components of the aerial device having movement relative to the anchorage and an attached lanyard connector. (ANSI A92.2)

You can add strap-mounted anchorages to the boom. If needed, the equipment manufacturer will assist you with modifying the bolt-on panels. I have seen anchorage connectors in the control box that can interfere with the operating controls, so when you order a new bucket, specify where the anchorages will be located.

4.9.4.2 Markings. Location of the anchorage(s) shall be identified, and the number of anchorages shall equal or exceed the number of permissible occupants. More than one occupant may attach to a single anchorage if the anchorage is rated and identified as being for more than one person. (ANSI A92.2)

4.9.5.1 Non-insulating buckets or baskets designed for use with insulating liners. These non-insulating baskets shall be constructed from non-conductive materials or when installed, be capable of complying with [A92.2] Section 4.10 Covers. The basket shall be identified as non-insulating. Insulating liners for these baskets shall be constructed from non-conductive materials and tested in accordance with [A92.2] Section 5.4.2.5. The liner shall be supported by the inside bottom surface of the basket. These non-insulating baskets shall not have drain holes or access openings. (A92.2)

4.9.5.3 Insulating baskets or buckets. Insulating baskets shall be constructed from non-conductive materials and shall have no drain holes or access openings. Insulating baskets shall be tested in accordance with the dielectric tests for liners [A92.2] Section 5.4.2.5. (ANSI A92.2)

You can use fiberglass buckets as insulating if you test them in the same submersion electrical test as the liners. This is allowed, but as with hot sticks, the testing and daily wipe-downs and inspections make it impractical.

4.10.1 Aerial devices intended for gloving work methods. Aerial devices intended for gloving work methods shall have covers for metal boom tip components of the aerial device that are exposed to conductor contact and are at risk of phase to ground or phase to phase current flow. (ANSI A92.2)

The fiberglass covers at the boom tip – the ones your workers keep knocking off – are required to use the bucket for gloving. Missing or damaged covers mean gloving is no longer approved.

4.11 Material handling rope. For synthetic-type rope(s), the average breaking strength shall not be less than 5 times the maximum working load. (ANSI A92.2)

I have found utilities using less expensive rope with a smaller diameter, but the rope you use must exceed five times the application, not necessarily the rating of the jib/winch. If you use a lighter rope, you must list the load limit – based on five times the new rope’s breaking strength – at the operator’s control station.

Following are the ANSI A92.2 categories of insulating aerial devices, which you can find at 5.1.2.

Category A. Aerial devices which are designed and manufactured for bare-hand work in which the boom is the primary insulation. All conductive components at the platform end shall be bonded together to accomplish equipotential of all such components.

Category A platforms are barehand platforms. A barehand bucket can be used for gloving provided that the platform is constructed of fiberglass and that the covers required by Section 4.10 are in place.

Category B. Aerial devices which are equipped with a lower test electrode system but are designed and manufactured for work in which the boom is not considered as primary insulation, but secondary to using insulating tools. Category B aerial devices require the use of live line tools with appropriate dielectric ratings. [Note: Check the manufacturer’s operating instructions; jibs do not have dielectric ratings]. These tools are to be depended upon for primary protection, just as in all cases where the boom is used as secondary protection.

Depending on your employer’s policy, this is a gloving bucket or a hot-stick bucket. Category B buckets are typically equipped with electrodes around the lower end of the insulating boom, making testing both reliable and convenient. A lower boom electrode uses a conductive band inside and out that completely encircles the boom.

Category C. Aerial devices which are not typically equipped with a lower test electrode system and are designed and manufactured for work in which the insulating system is not considered as primary insulation, but secondary to, using insulating gloves or tools.

These aerial devices are designed for gloving work and tool methods at 46 kV and below.

Category D. Aerial devices which are designed and manufactured for work in which the insulating system is not considered as primary insulation, but secondary.

Rated at 46 kV and below, Category D devices are not designed for gloving work methods and thus do not have to comply with Section 4.10, “Covers.”

Category E. Aerial devices which are designed for lower voltage applications.

Guarding or isolation methods can be used to accomplish insulation requirements. These units are designed and manufactured for work in which they are considered secondary insulation, not primary. They are rated at voltages of 20 kV, 5 kV, and 1 kV and below.

These last two rules appear in ANSI A92.24, which addresses MEWP training requirements.

5.1 Training shall be provided to MEWP operators and their supervisors and include the inspection, maintenance, use, application, and operation of MEWPs. Supervisors of MEWP operators shall also complete training as specified in Section 6.5 of this Standard.

5.2 Only personnel properly trained in compliance with this Standard and who have received unit-specific familiarization shall operate a MEWP. The user [employer] shall determine if personnel are qualified to operate the MEWP prior to authorization.

Conclusion
It is my hope that this information will help readers audit their bucket truck programs and eliminate the frequent incidents these rules are designed to prevent. Feel free to contact me with questions about anything you’ve read here.

About the Author: After 25 years as a transmission-distribution lineman and foreman, Jim Vaughn, CUSP, has devoted the last 28 years to safety and training. A noted author, trainer and lecturer, he is a senior consultant for the Institute for Safety in Powerline Construction. He can be reached at jim@ispconline.com.

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Photo caption: The cover missing in the photo above violates ANSI A92.2 rules, exposing flammable and conductive contamination. This bucket is no longer approved for gloving.