Holmes 850 Question

[Michael Drake]

We have a holmes 850 that has a custom hydraulic boom... I've heard both ways on this question and would like some more answers... Can I run a low line from boom to tailboard and out without damage to the gearbox... the owner had exploded a gearbox on his 750 years back and has been told to never do this with a holmes as they are not designed for it and it puts alot of stress on the gearbox... is this true with the 850 as well?

[mushspeed]

Michael....I have been working 750 s and latterly the 850  for many years and running low lines through a block  onto the transom and down onto the spades was a regular occurrence...they are an incredibly versatile piece of equipment and I cant see how it puts unnecessary  loading  through the box..

Providing they are regularly maintained....

I have broken hooks, chains, shackles and other things strained ....even bent a boom  .,.,....but we never  broke a gearbox ...

 

John.

[Michael Drake]

Thank you, I do not have too much experience with these. Just going off of word I've been told I can't imagine any additional stress but its concerning once someone puts the idea in your head who has had a gearbox break... could've just been its time to go tho.. 

2 minutes ago, mushspeed said:

Michael....I have been working 750 s and latterly the 850  for many years and running low lines through a block  onto the transom and down onto the spades was a regular occurrence...they are an incredibly versatile piece of equipment and I cant see how it puts unnecessary  loading  through the box..

Providing they are regularly maintained....

I have broken hooks, chains, shackles and other things strained ....even bent a boom  .,.,....but we never  broke a gearbox ...

 

John.

 

[GRUMPS The Towman]

I would have to take an educated guess and say that the gearbox failure happening during a low-line pull off the tail board was nothing more than coincidence. Like Mr. Coupland mentioned, I too have busted chains, snatch blocks, wire ropes and even bent a boom on a 750 back in the day and never had a gearbox let loose. Those old beasts are pulling monsters.

Edited November 12, 2020 by GRUMPS The Towman

[Michael Drake]

Noted thank you guys!! So in reality it shouldn't make a difference how hard the pull is off the tailboard?  I wonder if anyone else has had something similar happen to them?

[GRUMPS The Towman]

Well, keep in mind, EVERY component has it's working load limit of course. But for the sake of argument and simplicity I would say the limit of pull off the tail board is limited to the w.l.l. of the boom, wire rope and your rigging.

Working off the tail board your booms are closed in on center so you have their max rating at your disposal, 2- part the line ( or more if you have the line and rigging ) back to your casualty and multiply your wire rope's w.l.l. etc.. 

With your truck planted real good and the right rigging, She will pull a mountain.

[Michael Drake]

So here is the truck I'm working with... I'm sure some of you guys remember the post of it being built but Rustys towing... well we bought it from him and she's tank!! However this has been a concern of ours being that we need that low line pull from time to time.  And the boss having broke a gear box on a low line pull