Rob Gray :: ontheroad :: wothahellizat :: wot1 :: diaries :: issue-014


24 may 1999

A few tips I've picked up lately.

Chain slings Eventually you will have to get a chain block because the various items that need to be lifted just get too heavy. So there you are with your nice new chain block but it only has a single hook, not very usefull for lifting real-world objects.

What you need is a set of chain slings, but if you go to have them made up expect a bill for more than $300. As usual, and being the tight arse that I am, I went looking for another way and came up with drag chains as used by four wheel drivers. These are usually rated at ten tonnes and have a clevis hook at each end. At about $70 each (you need two) it's not an enormous saving but they are very usefull for other things as well.

I rigged them up as per the following diagram.

Note that they are hung over the block's hook at a point about one quarter of their length. To stop them changing this ratio as a load is applied I clamped them with D-shackles.

Here we have a very versatile slinging arrangment. You usually use the longer lengths to either hook directly to an item or loop the chain through it and hook it back to itself with the clevis hooks (clevis hooks are designed to hook over a link of the chain and provide a secure connection).

If the chain is too long for a given size of load it can be easily shortened by hooking the shorter end to an appropriate point on the longer end. As shown below.

Temporary slinging points Because of their shapes many objects don't lend themselves to being lifted by a crane. After stuggling with the rear body support assembly I decided there must be a better way. You see it's very inconvenient, and sometimes dangerous, to have one or two hundred kilos of steel suddenly slip sideways because the chains being used to lift it slid from their designated position.

The answer is to weld some temporary slinging points to appropriate places on the item to be lifted. It takes a few minutes but will make your life much easier and safer.

By slinging points I mean some loops made from pieces of scrap round bar. Cut two lengths about 150mm long and bend them in half at a rightangle.

Remember that the resultant "eye" (right arrow) must be large enough to pass a clevis hook (left arrow). The next photo shows a sling point on a long beam and a typical method of slinging where the clevis hook is passed through the sling point and hooked back to the chain.

And here we see the beam being lifted. Try that without some firm slinging points

These temporary slinging points can be quickly welded to an item then cut off when the job is done. Of course they can be used many times.

26 May 1999

The mounts are finally on so now it's time for the fun stuff, building the body. I already have the main cross members made so they just need to be dropped on. That's pretty much how it went down. They are too heavy to lift so few drive foward, winch up, drive backward, winch down cycles are required.

The next thing to do is weld the first uprights onto the rear cross member. Note the use of a large jigging square (top arrow) and a magnetic protractor (lower arrow).

The jigging square can be knocked up from some scrap angle and is invaluable as a clamping aid. If you make one don't complete the square right into the corner, this allows you to place a small tack weld or use it on an existing structure that already has a fillet weld.

The first two uprights are in place. Now we are actually starting to build a motor home body

Next I place the two main body rails in position

From here on things went so fast I forgot to take any photos.

27 May 1999

It's quite amazing, months go by with little obvious change in the truck, then within two days I have half a body in place. This is very gratifying work. It's hard going because the items I'm working with are very heavy, however you really get a feeling that things are moving along.

Some tools of the trade.

That will have to do as we're heading off to Queensland tomorrow for the Townsville rally.