A picture is worth a thousand words...
I have made progress with the Up Loop to Up Main turnout, excrutiatingly slow progress, and the captions explain some of the ups and downs of trying to build LNWR pre-1900 S&C work.
Photo 1 shows the toe of the switch... a loose heel switch blade with the toe supported by a real odd-ball of a fitting, rather like a marriage between a plain chair and a slide chair. Not available from any of the usual suppliers and unlikely to feature on any wish list... you do not want to know how many bits went ping in the making of just this one chair. I still have to make the corresponding chairfor the other switch rail. Thankkfully, there is just one more pre-1900 turnout at Hartley Hill and that is from the Down Loop to the Carriage Siding.
Photo 2 shows the same part of the turnout as photo 1, this time with the switch open to show how the switch toe tucks up against the jaw of the plain chair. The most difficult task so far has been training the gerbils to make nice neat holes for the drive rods from the under board Fulgurex to the above board switch blades.
Photo 3 has moved along the turnout towards the crossing... and shows the closure rail. Yet another "feature" of LNWR pre-1900 S&C practice was the use of 14" wide timbers and the absence of the expected "Bridge" or L1 chair. Where one might expect to see a bridge chair, as the closure rail approached the stock rail and thereby reduced the available space for plain line chairs, the LNWR used chairs which were considerably narrower than normal and hence enabled the closure and stock rails to be supported on separate chairs placed side by side on the same timber. The narrow chairs in this photo, where the timbers are marked "N", measure 0.160" in width... and at that there is b****r all holding the two jaws together. Failure rate is about 50% for these chairs so not for those of a nervous disposition, there are 24 of these narrow chairs in this turnout so a good thing that the majority of S&C work for Hartley Hill is the later circa 1909 arrangements.
Photo 4 shows the heel of the switch rail. "Loose heel switch" means that the switch rail can move relative to the closure rail because the fishplates at the heel joint are not tight. As a result of the loose heel joint, an "open" switch rail has a dog-leg appearance at the joint.
I have made the joint by using Exactoscale cast brass fishplates... soldered to the switch rail and pinned to the closure rail. As the switch rail can move in the heel joint then the only "block" chair for the switch rail has to allow for sideways movement in the switch. Yet again there is nothing to do the job from the manufacturers so I have made the block chair.
Starting with a plain line chair for the stock rail, cut away the base on the inside of the chair leaving the inner jaw, this is the first part of the block chair... then trim the base from the outside of another plain line chair which is on the switch rail and glue the two pieces together jaw-to-jaw. Now remove the switch rail... and remove the innermost jaw from the second part of the block chair. Replace the switch rail... set the rail in the open position... fit a replacement inner jaw against the switch rail without pressing the switch rail against the previous two bits-stuck-together - this produces a three-part block chair with space for two rails, the stock rail being held firm whilst the switch rail is free to rotate about the heel pivot. If you are following this then you have every right to doubt my sanity - or ask for a photo essay when I do the next one.
In this photo the final piece of the block chair is not yet fixed.... because if it was fixed then the adjacent loose heel joint would prevent the switch rail from being removed..... and I need to remove the switch rail to fit the stretcher bar as and when Colin advises on fitting the insulation to the drop link.
Apart from another pre-1900 turnout in the down loop the remainder of the S&C work is fairly easy... although those of you who have been reading the Hartley Hill Examiner may remember that Ganger Albert had a paddy just before he eloped with the barmaid. The local Civil Engineer had issued a work order for another turnout in the Up Goods line and the details required that Albert inserted the new turnout into the formation with minimum possession. As I recall, Albert was grunting and groaning (like an A-class) because the work order necessitated that the new turnout was constructed with interleaved sleepers between the switches and the crossing. So more research into what Albert did and what he recorded in his little black book.
regards, Graham
(I post the photos first and then edit the post to add the captions... amazed that this post got two likes before I had started the text!)