Gusset Plates

The gusset plates strengthen the area where the sole-bars, headstocks and diagonal beams intersect, and protect the headstock from the movement of the buffer shaft.



As you can see the plates are bolted to the sole-bars and to the diagonals, they aren't connected at all to the headstocks. The buffer shaft passes through the headstock and through a square hole in the gusset plate and then bears onto the end of the transverse spring.

The photo shows one of the better preserved plates but all are seriously corroded and need to be replaced.



We wanted to make the new gusset plates as like the old ones as we could, and we wanted to have fun with the forge. So I marked up the steel bench with positions for a jig round which to bend the new plates.



John welded the parts of the jig to the table.





Meanwhile the rest of the willing volunteers made smoke with the forge.



This is where I run out of pictures. Possibly shame, possibly in the heat of the moment I didn't take more.

Beating even red-hot half-inch thick steel bar to right-angles round a jig is not so easy as I thought it would be. And it helps if the jig is strong enough, which it wasn't. The jig broke as we were doing our first one.

We discussed re-heating the bar and finishing it across the anvil but in the end Ollie decided to fabricate the plates, welding three pre-cut pieces into the desired shape. It's a pity, I'd have liked to make them using blacksmithing methods but it would have taken a little longer.

Looking back at the process it was too hurried. Doing work like this needs very careful and slow preparation and a lot of thought. We didn't do that but rather made a hurried jig in pretty much the wrong place (too near the adjacent wall) which meant moving the bench. If we'd thought about the forces we'd be applying when we hammered the steel round we'd have made the jig stronger and might have succeeded in bending the plates round. Another factor was waste. Not wanting to waste metal we cut the bars only two inches longer than they needed to be to allow for trimming when finished, but this meant that we didn't have enough leverage to bend them, though this is a moot point because we'd have had to hammer them round anyway.

I've gone back to the drawing board to prepare details of how to make the gusset plates. We'll make them in two stages. First we will weld the long side that bolts to the sole bar onto the section that runs along the back of the headstock. When the timber frame is assembled we will fit the plate section that runs along the diagonal to get the correct angle and finally we'll spot and drill the hole for the bolt through the diagonal.

It's all a learning process.

Measuring, Marking Out, and (tentatively) Cutting

The job I seem to spend most of my time doing these days is measuring and marking timber for cutting or drilling. This is only partly a complaint. Accurate measuring is important and I enjoy doing it but I also enjoy doing more noticeable work, like drilling holes or making iron-ware.

I'd had a week off from the railway to go to my nephew's birthday party in London so I arrived there yesterday, Saturday 19th February, to find that the short longitudinals and diagonals had be cut to accomodate the draw-bar transverse springs. Before we can assemble them and the headstocks we have to drill through them so that the upper and lower parts can be bolted together round the springs.

My first job was to fit the diagonals and mark out the position of the oblique holes that are to accommodate the 1" tie-bars between the headstock and the transverse beams.



The tie-bar goes through the diagonal at an oblique angle as shown buy the red line. We decided to try to drill the hole ourselves. I marked the line of the hole along the top edge of the diagonal and projected the centre and edges down the face of the beam. I then marked the position of the centre of the hole down from the top of the beam. Ollie used a small diameter twist bit to drill a pilot hole to guide the flat-bit that we would use to make the hole. I then cut a wedge out of the beam face deep enough at the centre-line of the hole so that the full radius of the flat-bit would make contact with the face of the timber. We began drilling. It went well for a while but coming in at such an oblique angle meant that we had to put a long extension on the drill-bit. Keeping the drill perpendicular to the lines was difficult and in the end as I withdrew the rotating bit from the hole it snagged and bent the shaft as well as doing some damage to the timber.



We decided that it would be better if Mark, the carpenter who made the frames and who has better tools at his disposal would drill the holes. So Ollie called him and asked him to do just that.

So now we have a pile of timbers marked up ready for Mark to drill the diagonals and for Ollie to drill the holes for the 5/8" bolts that will hold the diagonals and short-longitudinals together.



I had a moment of realisation as I looked at the diagonals and longitudinals. I understood at last why they are jointed into the headstocks and cross-beams as they are. With the whole frame completed it will be possible to drop out the bottoms of the diagonals and short-longitudinals and raise the transverse-springs into place before putting the diagonals and longitudinals back together to hold the springs in place. I had thought we'd have to insert the springs before we finished assembling the frame!

Frame Building

Mark, the man who's making the timber frame, came to Bitton to begin assembling it last Tuesday.



I couldn't be there to join in so I was curious about what I'd find when I went in on Saturday. What I found was this:



As you can see, the sole-bars had been put together with the cross members and temporary tie-bars installed to hold it all together.

One of the longitudinal end beams is missing, it's over length by about an eighth of an inch, so Mark has to do a little work on it.

The whole frame was set up on blocks awaiting installation of the headstocks.

Today I wanted to get out and I fancied a cycle ride, so I rode out to Bitton along the cycle path and found the team working on the frame.



Mark is raising the headstock at this end, he's already located the other end onto the tenons on the sole-bar. Roger is winding the nut on the tie-bar along ready to begin tightening it all up.



The joints are good and tight and the timbers very heavy, so there was a lot of levering and hammering to get the whole thing together.

During a break in the assembly we decided to check that the fittings would fit. Ollie got one of the buffer bodies out of the shed and we put a couple of the sole-bar to headstock straps in. These hold the outside edges of he buffer body.




The sole-bar straps can be seen hear against the inner cheek of the sole-bar. I had some trepidation about whether these would fit properly but when I got the first one and inserted it through the headstock it fit perfectly.

We also checked that the draw-hook would fit.





Lastly Mark returned to the job of marking up the diagonals for cutting and preparation to put into the frame. He's taken them away to prepare and to cut in the slot for the transverse spring that bears onto the buffer ends.