All but the two holes where the bolts go through are redundant, I may at some time saw off the excess but it's a faf to take it apart, and it's okay how it is.

The axel has been sawn in half and rebolted to another bar. I am confident this gives it enough strength.

The bracket protrudes out from the edge of the trailer, but not enough to interfere with the spokes of the wheel.

The axel isn't bolted directly to the frame at any point. This means that it can be moved to a different point on the trailer if necessary.

The middlemost bolt just goes through the axel end and intermediary bar, the outer two are fastened through the L bracket at the end as well.

The bracket and the axel simply squeeze the frame tube to keep the axel in place.

Everything here but the pin (and the bike) is from www.bikesatwork.com. The pin is a 6mm carriage bolt. Because of the way the pressure is exerted on the hitch, the pin won't jump out even if it gets jolted very badly.

Rear perspective, high-vis jackets are strapped on to the middle. You can just about see the length of the thing and get an idea of what kind of size of thing can be carried.

This supporting strut has an L bracket on the top and bottom, held by four 6mm x 50mm bolts.

The towbar has arguably the weakest attachment, with four 6mm x 50mm bolts in all attaching to U brackets on the underside. Extra care has been taken to ensure that the supporting strut (right) is tightly secured to the frame to allow for the forces that this area is under.

Two heavy duty U brackets keep the towbar in place by constriction. This allows that the towbar rotates if pressure is applied to the bend between the trailer frame and hitch, but this is not a problem as pressure is never applied here when hauling even the heaviest loads.

Two bearings fit inside the wheel hub, then an aluminium spacer separates the bearing and pin to minimise friction.