F-Ribs And Sibs - Inflatable Boat Community

I've attached a picture to show you what the previous owner has done. My question is, if I was to sight the jockey holes central, which will stop the jockey twisting etc... will I effect the over all strength of the box section by moving the holes 3-4 inches?

Or should I have the local metal works weld over in 1st?

Hmm, centring the mount will certainly make it look better and resist twisting in one direction more than it currently does.
The concern with leaving the holes is that it will leave a space into which the steel can move during a collapse. The big issue is that they are so close to the top, meaning that there is less side wall to take the sheer loads at that point.

The simplest fix is to move the jockey wheel and then put bolts through the dodgy holes so that there is no way the box section can collapse (as the bolts are in the way).

There are other factors to think about - what was the design load of the trailer and what load do you currently have on it - for example if it is a trailer rated for 350kg but you only have a T38 on it, weighing about 110kg then the strength lost through the holes won’t make much difference, but if you are near the peak loading of the trailer then it would have a greater impact.

Can you give us some more info?

Not going into the strength versus holes in the side of a beam, if it was my trailer I would weld 2 to 3mm plates either side of the draw bar over the holes and re-drill them central.