11 replies to this topic

[Tha Bobster]

October 3, 2005
Wooden Transformer Pole Gins

Purpose
To inform employees of the need to remove all existing wooden transformer pole gins from service and replacethem with current rated, newer-style pole gins.

Situation
A crew was in the process of changing out a 25kvA transformer to a 50kvA transformer in a “pack-in” situation. A transformer pole gin was used to remove and install the transformers. When the new transformerwas raised, the wooden transformer pole gin failed, breaking in half. The journeyman lineman who was on the pole preparing to install the transformer was injured.

Recommendation
Remove all wooden transformer pole gins from service and replace them with current rated, newer-style pole gins. See examples below of newer-style pole gins (Hastings and Chance).

It is imperative that the ratings of current transformer pole gins are known so that lifting capacity is accurate and known before being used.

 woodgin.jpg   42.54K   462 downloads

Hello Guys
On august 4 2005 i was involved in a failure of the wooden abchance TX gin in a rear lot TX change out the rating of this gin is 1500# / rated 650# single line pick we was lifting 574# single line pick when it broke in half see picture attached 1300# was the most this ever saw when we were pulling it up when it broke the top part with the block and rope went between my safety and legs the swing of the rope went up and wrapped around the secondaries and tangled up as the weight of the TX was going down to the ground it pulled me up and over the secondaries by my right leg pinning it and myself to the pole the weight came to a sudden stop when the 1" rope came tight I heard the pop now the rope is still slipping around the back of my knee rope burning my leg as its slipping I grabbed my knife by the grace of god cut it free and when the last cut was made it launched me around the pole like a rag doll..........the out come well Left knee MCL torn Left foot broken @ the arch Right foot too....sprain to my right ankle torn MCL , popped ACL Pulled right in half broken Tibia and Fibula , pulled Sprained Performous ligament right hip , lower back sprain , middle back sprain , bulged disk in neck , really sore shoulders any rate the only surgery to date was the ACL in the right knee.been in Therapy since October every day for 5 hours getting around kinda gimpy and limpy but still have the leg and it kinda works so if you have any way of spreading the news it would be a good thing

David J. McCoy
"PacifiCorp Journeyman Lineman"
American Fork, UTAH

Attached Files

•  woodgin.jpg   42.54K   298 downloads
•  DSCN0634.jpg   45.8K   294 downloads
•  DSCN0633.jpg   44.93K   238 downloads
•  DSCN0632.JPG   46.12K   254 downloads
•  DSCN0631.JPG   69.69K   244 downloads
•  DSCN0630.JPG   73.44K   260 downloads

[crippledlineman]

Oops, just posted this in the High Voltage forums also We can move my thread if you want.....

[Utility Innovations]

I know of a few more incidents involving broken transformer gins. It can happen with steel and fiberglass gins as well. A side pull and using a snatch block up top which doubles the strain on the gin were two reasons. In this incident a the rigging was "a single line pick". I am not familiar with the term, can someone explain how this gin was rigged.

Wayne

[Kevin]

Was the rope inside the linemans safety?
If it was that is not a good place for it to be.

... add a second block to the system to reduce the weight on the gin.

[jimvaughn]

Let's talk about rigging. There are two stress components to rigging from a gin. The down-haul weight is the pull on the rope required to lift the load. The load weight is the weight of the load. When the load is resting the stress on the gin is just the weight of the load. When you pull down on the load line the stress on the gin is the load weight plus the down-haul weight. No matter how many sheaves there are in a block the top block attached to the gin still has the whole weight of the load plus the downhaul weight. Adding sheaves to the rigging decreases the "down-haul" weight on the gin but has no effect on the "load" weight on the gin. The reduction of down haul weight is figured by dividing the load weight by the number of lines or parts in the rigging. Using a single rope, the stress on the gin is the transformer weight plus the down haul weight which with a single line is equal to the transformer weight. When we train apprentices we put a dynamometer between the gin and the block so apprentices can see the stress on the gin. The one that broke was rated for single line pull at 650 pounds or an applied load to the gin of 1300 pounds on a gin rated for 1500 pounds. You guys used the right gin as far as rated for the lift but it still broke. We had a fiberglass gin fail a few years ago so we tested some by pulling them to destruction between two bull dozers (we tried trucks but we couldn't control the strain) and a dynamometer. We stopped pulling when they started to crack, not very scientific but it was good information to know. We broke three gins (old fiberglass) and all of them failed between 6 and 8 thousand pounds. We figured that is a 3 to 1 safety factor. my next thought is this, Iv'e been doing line work for 35 years, I don't think a wooden gin has been sold by AB Chance since the 70's, probably more like the 60's. How old was the gin that broke?
Thanks for posting the photos, good for teaching how frail the human body is.

October 3, 2005
<span style='font-size:14pt;line-height:100%'>Wooden Transformer Pole Gins</span>

Purpose
To inform employees of the need to remove all existing wooden transformer pole gins from service and replacethem with current rated, newer-style pole gins.

Situation
A crew was in the process of changing out a 25kvA transformer to a 50kvA transformer in a “pack-in” situation. A transformer pole gin was used to remove and install the transformers. When the new transformerwas raised, the wooden transformer pole gin failed, breaking in half. The journeyman lineman who was on the pole preparing to install the transformer was injured.

Recommendation
Remove all wooden transformer pole gins from service and replace them with current rated, newer-style pole gins. See examples below of newer-style pole gins (Hastings and Chance).

It is imperative that the ratings of current transformer pole gins are known so that lifting capacity is accurate and known before being used.

 woodgin.jpg   42.54K   462 downloads

Hello Guys
On august 4 2005 i was involved in a failure of the wooden abchance TX gin in a rear lot TX change out the rating of this gin is 1500# / rated 650# single line pick we was lifting 574# single line pick when it broke in half see picture attached 1300# was the most this ever saw when we were pulling it up when it broke the top part with the block and rope went between my safety and legs the swing of the rope went up and wrapped around the secondaries and tangled up as the weight of the TX was going down to the ground it pulled me up and over the secondaries by my right leg pinning it and myself to the pole the weight came to a sudden stop when the 1" rope came tight I heard the pop now the rope is still slipping around the back of my knee rope burning my leg as its slipping I grabbed my knife by the grace of god cut it free and when the last cut was made it launched me around the pole like a rag doll..........the out come well Left knee MCL torn Left foot broken @ the arch Right foot too....sprain to my right ankle torn MCL , popped ACL Pulled right in half broken Tibia and Fibula , pulled Sprained Performous ligament right hip , lower back sprain , middle back sprain , bulged disk in neck , really sore shoulders any rate the only surgery to date was the ACL in the right knee.been in Therapy since October every day for 5 hours getting around kinda gimpy and limpy but still have the leg and it kinda works so if you have any way of spreading the news it would be a good thing

David J. McCoy
"PacifiCorp Journeyman Lineman"
American Fork, UTAH

[Kevin]

A 3:1 MA will reduce the weight on the upper block considerably.
A weight of 500lbs. on the lower block will be reduced to 333lbs. on the upper block.
The worst thing you can do with any load is let it drop and stop it suddenly creating a shock load which can be several times the weight of the object .

[TexasLineworker]

I don't think a wooden gin has been sold by AB Chance since the 70's, probably more like the 60's. How old was the gin that broke?

Good question. But, I do see them from time to time on Ebay.

[Jos Lapointe]

Best wishes for the new year
It the first time that I read about a wood jib pole I been in the industry seen the 70 and we alway use a AB chance jib pole. We use it to lift 167 kva transformer.
Hope your friend will recover from is injury

[djwires]

I don't think a wooden gin has been sold by AB Chance since the 70's, probably more like the 60's. How old was the gin that broke?

Good question. But, I do see them from time to time on Ebay.

Hello I'm They guy that it happened to still not even 50% of what I was before although I was able to compete in the lineman National finals in Kansas City our team did finish in the top 25 (of the ones that finished in last) had alot of pain pills in me and had a great time.........the gin pole was about 40 yrs old same as me lookeded to be in great shape was looked over by OSHA here in Utah they said we should have been able to tell it was going to break (guess now we have x-ray vision to go along with our amazing strenth) my company gave me a letter of accomidation and a Plaque as well as the crew our safety dept found nothing we did was in error scince they have removed all wooden gin poles from the property......stay cut in thanks david j mccoy

[639trbl]

THANKS FOR THE INFO, AND GOOD LUCK WITH YOUR RECOVERY

ALL WE'VE USED HERE, ARE THE METAL ONES, ALTHOUGH WE DO HAVE SOME OF THE NEWER FIBERGLASS MODELS........

[strange052]

Djwire,
Welcome to the site!
Glad you are doing well and good luck with the rest of your recovery

[bestbudfam]

Great post. Useful info, thanks.