Welded lifeline stanchions on a steel hull - pipe or flat bar?

Roller bender pictures

OK, a few pictures of my roller bender.

The base is a T made up of 2 pieces of 150mm parallel flange channel. Slide grooves cut using corner drilled holes & a cutoff wheel in an angle grinder. No need for milled accuracy.

Wheels are approx 150mm OD by 12mm thick bored for a loose slip fit on pins made from 50NB Sched 80 pipe welded to base plates. I put the weldments in the lathe and took a skim cut over them to remove weld distortion and improve the surface. The wheels are a sandwich with PVC shaped to the size I wanted, in this case 20NB pipe diameter. You can swap out the centres for other pipe sizes. So far I haven't but I will.

Force is applied via a 10 tonne porta-power. The sliding part has a captive plate underneath to keep the wheel from rising, which it tried to do until I added the restraint. Just a reasonable fit, nothing really precise.

Rotation is by the armstrong method, slipping a bar through the bit of RHS attached to the 3rd wheel.

You need to set up pipe supports or you'll end up with a spiral. Guess how I know that....

Takes less than 10 minutes to put in the bend shown into 9m of pipe.

Basically self-explanatory really.

I made my roller flanges because I had the steel to hand, I had the plasma cutter & lathe, and I'm an idiot. I should have bought weld-on pipe flanges and saved myself the time & materials.

PDW

 

A mini bender

Sometimes you don't get the bends quite right or it's all to hard to do on the floor. That's when this little device comes into play.

I made it for a specific pipe size - 20NB. The half pipe sections welded to the T piece are cut from 25NB as is the pusher.

The thread is a length of M16 threaded rod.

Construction is crude, simple and needs only a welder and grinder. The thing works quite well. Having 2 nuts is a waste of time, 1 is quite sufficient.

A few pix....

 

You're doing a great job....keep it up

 

Thanks.

I do a crap job of out of position MIG welding on stainless steel but fortunately a flap wheel conceals a lot of the evidence.

Could have used TIG but there I'm 30 years out of practice and didn't fancy trying it while standing on a ladder. At least MIG is fast and you get to hold on with the free hand.

PDW

 

You look to not have much space for a good sized anchor and it looks like the chain run is in the way of the large cleat.

With anchor stowed the cleat will be beneath the chain!!!

Anchor stowage, retrieval and chain management is an art. You need a wash barrier too to keep all the mud up front so it does'nt wash down the decks.

 

Thanks for posting those. I will be replacing my bulwark cap tube shortly (once I can find the right section) and I know I'll never get it fair unless I bend it before fitting it.
I am thinking of doing the bending by curving it with a tackle and heating the compression edge at intervals to upset it slightly...but a roller would be much more elegant.
Your work looks really clean and fair.
Nick.

 

From a humble opening question this turned into a great thread.

 

Looks good PDW
Doing the bow railing sweep can be done without a roller, mine is about the same at the bow as yours, what I did was bent the U section out of a couple foot of pipe bending the U at about 10% less than what was needed then weld the long pieces straight to it on the ground, then after the uprights are welded on and fish mouthed lift the assy up on there and by pulling in on the pipes aft gives you a lot of leverage lightly tack it in position after it's pulled to shape, Next before welding make up some wedges to fit cross ways between upright spans, what your doing here is bending the curves out an inch or to to compensate for the weld heat/pull and also stick upright props wedging the railing upwards between uprights then cold weld it say 1/2" long welds letting it cool and coming back with another 1/2" weld till it's finished. 1"x 4" or 2" x 4" wood with a v cut in the ends make for nice wedges and props .

 

Depending on the stiffness of bulwark and size of tube? You should be able to use full length tube and start at the bow using short hot tacks spaced about 2" at most, the closer the better, letting it cool before doing more with a helper out at the other end of tube

 

Tazman
(My project is a rebuild) I have already changed the rubbing strips on both sides which were made from box section with the back cut off. I bent those around as you describe with a tackle and tacking them before welding fully. It was easy to do but I wasn't happy with the results. When you stand back you can see the bend isn't fair. I think if I could create a fair curve before starting I would have a much better chance of fitting it right.
Nick.

 

Appearances in photos are deceiving and given the source of the criticism I really can't be bothered entering into a discussion about it. I don't recall ever seeing you post pictures of anything you've built let alone tools you've built to build things so frankly your opinion of how *I* do things it irrelevant.

PDW

 

Thats because you have'nt been here long enough or bothered to look.

I think for you learning the hard way is better.

 

That reminds me something...ah, yes me!