Point rodding

The question of what sort of track I should use is discussed on the ‘Phase 1’ page. All that needs saying here, is that (probably wrongly, in retrospect) I went for Tenmille plastic-sleepered track.

Although one day I will no doubt end up replacing the Tenmille points, they'll stay where they are until they fall to bits. One thing about Tenmille points is that they don't have over-centre springing like Peco points. So they need a point lever to hold them over. There were (and still are!) only two points at Butterknowle (one leading off the main circuit, the other providing two lines in the station) but they are rather inconveniently placed for operating with a lever right next to the point. So, in good prototypical fashion, some point rodding was called for.

The rodding itself was made from galvanised wire (from coat hanges, as it happens) although brass would have been better. But that would have meant going and buying some! In reality, rodding is carried on rollers mounted in frames (“stools”) as in the drawing which shows the arrangement for ‘channel’ rodding. On the HLR, it runs in guides made from short lengths of aluminium angle with a clearance hole for the wire in the vertical side. The other side is screwed down to the track base and eventually covered over with ballast. The photos give an idea of the finished result. Not entirely prototypical, but it works!

Partly because the wire I used wasn't quite long enough, and partly to allow some adjustment, I included a number of the brass terminal blocks cut from small electrical terminal blocks. They're just visible in some of the pictures.

Tenmille point levers were used to control the points, except that the threaded plastic insert which is connected to the point was replaced with a lubricated brass screw as the plastic is quite stiff and tries to turn the point rodding rather than just rotate in the body of the point lever. The two levers were mounted on a piece of ply. Some stiff wire, soldered to the head of the screw, connected with the first crank in the point rodding.

The cranks are fettled from a piece of aluminium sheet. A bit of trial-and-error suggested that about 1" was about right for each side of the crank. As you'll see in the pictures, two or three holes were drilled in each arm to allow the throw of the crank to be adjusted. The arms were made as narrow as possible, but some extra material was left on the inside of the angle to allow a rather larger pivot hole to be drilled. I found it was quite important to make all of these holes just the right size to allow everything to move easily, but without any sloppiness. Otherwise, too much movement is lost over the length of the run. The crank turns on a brass roundhead screw with a couple of washers and a plastic spacer cut from some old kitchen furniture fittings.

It probably doesn't matter very much on this relatively short length, but some degree of compensation was incorporated where the longer run of rodding has to cross a track. This is easily achieved by making sure that the point rodding is pulling on one side and pushing on the other. (See inset box.)

When all was completed and set up, I was pleasantly surprised that it all worked, especially considering that the longest run is about 6ft and includes four cranks; perhaps not much for some, but complicated enough for me! It does take a bit of fiddling to get just right and it's important to allow for adjustment by including some means of varying the length of rods, and also of adjusting the throw of cranks by drilling several holes in each. Subsequently, it's needed minor tweeking from time to time, and a regular dousing with oil to keep everything working smoothly.