Thread by @cocteautriplets

Tremendously exciting! A pulley transfer and cable inspection pit, sith it's c. 9 foot pulley wheels sitting just below the surface!

https://twitter.com/aljaroo1874/status/1428316788631220226

And what I think/hope is the lights and/or telephone for the cable watchman

cc @Scotindustria @Mikeashworth12 @BillHarvey2

I made a simplified animation to show what would happen here. There are 2 big pulleys, each with their own constantly moving cable loop. A tram car has 2 grippers to attach itself to the cable, and can move between each section of cable by alternately gripping and releasing them.

This is how cable cars negotiated switching between different lines (and haulage cables) at points or junctions, and how the Edinburgh cars coming down to Pilrig would reach the end of the line before switching onto the other track to head back uphill.

The haulage cables were powered by stationary steam engines in the powerhouses at Shrubhill, Henderson Row, Tollcross and Portobello, where there were also big cable tensioners. They were endless loops that ran around the network via an elaborate system of subterannean pulleys.

The cables ran at a constant 12mph, and therefore cars could either go at 12mph or stop. Coasting by gravity was not allowed except at certain approved places, to speed up the movement across junctions.

The network kept junctions to a minimum by design, as they are a weakness in a cable system, but they were not avoidable. The main ones had inspection pits underground, staffed by a man or boy whose job it was to watch for any cable damage or coming off the pulleys

Wherever the cable snapped or came off the pulleys, that cable would have to be stopped at the winding house and either set back onto the pulleys or re-spliced. To report back to the power house, each pit had a direct telephone.

This 1907 PO plan (NLS) shows the Shrubhill power station and the short section of cable tramway down Leith Walk to Pilrig. The municipal boundary (dashed line) runs up Pilrig Street, where the Leith Corporation electric network (green) runs before turning onto Leith Walk.

This resulted in the infamous "Pilrig Muddle", where you had to swap between systems to continue your journey. Here a cable car loads almost exactly where this pit is, while Leith cars (with their current collector poles) glide by in the background. (pic Edinburgh City Libraries)

There was a less well kenned "Joppa Muddle" (Joppa Jumble?), where you left the Edinburgh cable system and joined the electric Musselburgh system. But it at least was at a network end, not the middle of a principal route flickr.com/photos/johnmig…

The Pilrig Muddle was unmuddled in ~1920 when the Edinburgh Corporation system took over Leith Corporation, and moved to the same electric traction as the latter. Here we see work at Pilrig, over the wheel pit, to make that connection

https://twitter.com/cocteautriplets/status/1334429657249275904?s=20

The cable cars are easily identifiable by the 4 spoked wheels on bogies at each end, and a large capstan on the driving platform for applying the parking brakes. Electric trams had a 4 wheel truck in the centre, and of course a current collection pole

https://twitter.com/ThelmaScotland/status/1358735182845652994

One thing that stuck though was the word "car". Even though it was a tramway, a "car" was the official word for the vehicles, and was the colloquial phrase for a tram.

https://twitter.com/cocteautriplets/status/954317517459279872?s=20

And while we're here, let's once again recount the tale of the "Battle of South Clerk Street" that took place on opening day of the through electric tram service from Pilrig to Liberton.

https://twitter.com/cocteautriplets/status/955559146061025281?s=20

And finally the rise and fall of tramways in Edinburgh and Leith in a little animation showing the different networks from Horse to Cable to Electric, how they spread, were merged together, grew, and then quickly cut back to nothing in a few years.