Author Topic: Dismantling Bridges (Read 3090 times)

Paul_H · « **on:** August 07, 2005, 01:56:09 am »

I got a call earlier this week from a guy that used to be head of road engineering for the local forest district but is now a freelance contractor for the MOF.He was wondering if I was interested in working with a crane to dismantle a couple of bridges.One is a 70' Bailey bridge that was wiped out in the flood a couple of years ago and the other is a standard log construction with a needle beam and brow logs added after things started to sag.

The bridge is twisted pretty bad and they want me to cut the deck up with a saw and remove the planking then hang from the crane with a cutting torch and remove one 10' bay at a time so the crane can manage the pieces.

I was up looking at it again tonight and wondering if it would be safe/easier to remove the deck and the outside trusses then cut a couple of bays at a time? my only prior experience with Bailey bridges was driving across them and am hoping some of you here have had experience building or dismantling them and could pass on a few pointers.

This nest was the main reason for going up there tonight.We gave it a good shot of the bug bomb and hope they will be gone by Tuesday

The last pic shows the far end of the bridge buried to the top with gravel.

Tom · « **Reply #1 on:** August 07, 2005, 08:34:14 am »

None of that looks too safe by my standards. How do you get volunteered for stuff like this?

Hanging from a crane with torch?

$:-\$

Even the hornet's nest seems a minor concern when you have steel buried in rock and gravel in a running river. Don't do anything stupid. We don't want to hear of your 'life flight' to the big hospital.

You're going to need a mighty good crane operator, Paul.

OLD_ JD · « **Reply #2 on:** August 07, 2005, 09:13:40 am »

wow....that ain't look like a easy job

Paul_H · « **Reply #3 on:** August 07, 2005, 11:02:48 am »

Tom,Old_JD

The bridge has no water running under it right now so it isn't too bad to move around below the structure.There is an excavator heading up on Tuesday to ramp down onto the river bed to allow the crane to work along side the bridge.

This is the bridge that I don't like the looks of(same river,8 km below Bailey bridge)

It might be hard to see but I'm pointing at some cables used to lash the needle beam.They need to be cut along with the cables on the other end of the beam,then the side logs will be removed and what is left of the decking.After that the 5 main logs will be pulled out.
Three of the logs are basically mush and have broken off of the cribbing.
The span is around 40'

I have no problem saying No! if not comfortable.

Kevin · « **Reply #4 on:** August 07, 2005, 12:07:23 pm »

Quote

Riding hook or load

14.51 A worker must not ride on a load, sling, hook or any other rigging equipment.

Paul;
I hope they have a proper work platform/cage or you may not have any insurance.
If they want to suspend you off the hook it could be very dangerous, even with a full body harness suspension trauma is a reality.

Frank_Pender · « **Reply #5 on:** August 07, 2005, 04:08:32 pm »

I would work from a remote position and a plunger device with some wiere attatched to the plunger and the other end to a few round piesces of powder wrapped very tightly with red paper.

Furby · « **Reply #6 on:** August 07, 2005, 04:14:40 pm »

Faster and easier, eh Frank?

Paul,
Make sure you have some one there taking pics!

I wanna see, it sounds like fun......with an edge.

Paul_H · « **Reply #7 on:** August 07, 2005, 04:33:10 pm »

Kevin,
I talked to the crane operator and he told me he will supply a basket and he and I are on the same page as far as safety is concerned.

Frank,Furby
I agree,that log bridge should have a Viking burial.Wait until November and set match to it.If it was my decision,it would be pulled apart with a line loader with a grapple.Nobody out there on deck and the ability to let go of the logs if the machine tips.

Woodcarver · « **Reply #8 on:** August 07, 2005, 04:50:52 pm »

Back in my college days I spent a summer working for a bridge construction company.

One of my assignments was to hang in the bucket of a crane and cut the reinforcing steel in a bridge that was to be replaced. I cut a piece of steel that was bent and under tension. One of the cut ends struck the torch sending it flying and bending it beyone repair. Fortunately it missed my hand completely.

Furby · « **Reply #9 on:** August 07, 2005, 05:07:10 pm »

Paul,
I agree the wooden one looks like fun, but how big of a crane can you get to the site?
I'm wondering based only on what I see in the pics if it would be possible to pick the whole thing up and swing it away from the river?
While 40' is a bit, it's really not that much for some cranes and you could get an estimate on weight using some of the calculators here. They would figure out to be green, but I figure there has been a fair amount of tratment added to the logs over the years, and the green weight would give a bit of a cushion.
With some proper rigging placement, I would think it would be a lot safer and probly easier to move it all at once and either left to rot or disassembled away from the river.

The metal one reminds me a bit of cutting logs. Watch for pinch points and use the same methods one would when bucking a tree in difficult situations. I'm guessing the hardest piece will be the one under the gravel, but at least the gravel will help to stabilize the rest of the structure during the demo.

Frank_Pender · « **Reply #10 on:** August 07, 2005, 11:49:00 pm »

Paul, I am not able to see the entire end that is out of the water, but how about throwing a line around the water end and using the bulkhead where the bridge is resting as a pivot point, then swing the water end onto the same shore and the pivoted end? It is easy to offer advice from a thousand mile away, ye?

Paul_H · « **Reply #11 on:** August 08, 2005, 12:04:51 am »

I'm not sure why they want to play around with the crane when there is perfectly good logging equipment nearby.I don't think a D8 Cat would pull the bridge by itself,even with a luft line but a Madill 070 mini tower anchored into the rock behind(pic5,after wasp nest) would have the lift and pull with a couple of blocks to drag the 3/4 of the bridge to level ground out of the creek bed.The rest of the bridge would have to be dug out with the excavator.

I have to phone workers comp tomorrow and see if I can get coverage for me and a swamper.If I can't we'll be out of luck unless I can piggyback on another contractors comp. $:-\$

etat · « **Reply #12 on:** August 08, 2005, 02:33:36 am »

Personally, I'd be dang scared to hang from a crane with a cutting torch. That said, I would LOVE to be there and watch you do it!

Rod · « **Reply #13 on:** August 08, 2005, 07:22:56 am »

I think I'd pull the bridge out with a dozer,and if that didn't work hook another dozer and have 2 of them pulling.And you could use one dozer to drop the blade and push stuff off that might cause the other dozer from pulling the bridge out.A dozer the size of a D8 rents for $60 and hour with an operator around here.

I have know idea if my idea would work tho.

Kevin · « **Reply #14 on:** August 08, 2005, 07:31:29 am »

It should Rod, A few logs under the frame for the bridge to roll on would help too.

Engineer · « **Reply #15 on:** August 08, 2005, 10:43:14 am »

I wouldn't bother with a crane for any of that. There isn't much to either bridge that is worth salvaging, from the pictures; so why not get a big excavator with a hydraulic thumb or grapple (something in the 40-60 ton class, like a Cat 345 or 350) and sinply park it on the bank and reach in for bits and pieces? Then you can safely cut it all apart on the ground, and not risk life and limb to play with a torch hanging in midair.

A big machine like that typically has a 30-40 foot reach minimum, so even if you has to park it partly in the river, you should still be able to get all of it out of there. Plus, the big excavator can rearrange some of those river boulders, get the gravel off the buried end, and remove the headwalls or piers if necessary.

Scott · « **Reply #16 on:** August 08, 2005, 04:06:38 pm »

Paul, I can't really offer you any advice on how to go about doing the work but i definatly want to see some pictures of you guys working and the equipment your running

spencerhenry · « **Reply #17 on:** August 08, 2005, 05:28:35 pm »

an excavator with a thumb is an amazing piece of machinery. a friend of mine around here does alot of work in rivers, according to him, the machine and the operator have to be certified to work in a river channel. the machine cant have ANY leaks. assuming you can work in the river bed with a machine, i think that would probably be a good way to do it.
what species are the timbers? is any of the wood salvageable (not rotten)? reclaimed wood is very popular around here, and commands top dollar.

Kirk_Allen · « **Reply #18 on:** August 09, 2005, 04:28:07 pm »

Dont know squat about dismantling bridges but from the looks of it, I want to be the one hanging from the crane with a torch

What a story for the grandkids. I can add that to my roof top gorilla story for some real adventer

Sure wish I was closer Paul. I'm with Furby. Looks like a fun project.

OK, I think I am twisted when it comes to fun but it realy does look like fun

WH_Conley · « **Reply #19 on:** August 09, 2005, 06:34:31 pm »

Hey Kirk, if it wasn't so far we could both go.

I have done a lot of cutting and welding from a man basket. Three things that are a must, good operator, look the job over ahead of time and get your plan togather and mainly DO NOT GET IN A HURRY!!!!!!

If at any point you don't feel comfortable, get away from it and re-evaluate the situation.

I been following this thread from the start, having withdrawl symptoms I guess, after doing that kind of work it's kinda to get away from it, not as bad as sawdust though.

Paul, sounds like you have been getting some good advice and ideas, if at any time I can help with my limited knowledge let me know.

Bill, UBC, Piledriver

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Author Topic: Dismantling Bridges (Read 3090 times)

Kirk_Allen