High-lift shoe gear

IIRC, battery locos can lift all their shoes clear of the rails in order to avoid the loco's batteries livening up an otherwise dead section of track. That may have an impact on how the central line high-lift works.

Now thats interesting, as in a previous thread a few years ago, somebody stated that the 72ts that transferred to Hainault didnt need high lift shoegear fitted.

www.districtdavesforum.co.uk/thread/22921/unusual-train

Contains links to even older threads, sadly with many long lost members. However, all roads seem to lead back to towerman !

Were the 67TSs on the Loop not transferred via the Loughton Branch Junction - Leyton Station Junction line and a diesel shunter?

When we took a 72TS unit to Woodford in the 80's to exhibit with the 1986TS prototype units, it went via the central area tunnels. I don't recall whether it was battery loco hauled, but it might have been.

I seem to recall a lot of problems with the 92TS shoegear in the early days. There's a "frangible link", designed to break rather than rip the shoebeam of in the event of a snagged shoe. Think it took a few attempts to get right - with the odd lost beam and a lot of missing shoes. Again from memory, the Central Line suffered more often from tipped conductor rail when the shoe caught on the side.

The missing shoes used to exacerbate the issue with ATO trains getting gapped at Ruislip. If there'd been wheelslip/slide the ATO could get lost as it encountered the points PAC at an unexpected location (counts wheel revolutions from last station) and stop the train ... right over the points gaps in the conductor rail. Meant dragging jumper leads out from the depot.

The connection was removed in 1971, but 1967 stock were still running on the shuttle, turn-about with the 1960 stock, until 1984. www.flickr.com/photos/davidh73/43411142641

The Hainault-Woodford line, and the 1960 stock, were converted to manual operation in 1986.

My first journey on the Hainault shuttle, in 1977 I think, was on a 67TS.

The only TS that couldn’t run through the original CLR tunnels with shoe gear down was 38TS.

The positive rail in the tunnel sections is set higher than normal on other lines, requiring the trains to be fitted with 'high-lift' shoegear.

Could it be that the CLR tunnels were narrower than later lines.

As mentioned above and elsewhere, from 1900 until 1940 the Central London Railway, today’s Central Line operated with a single power rail initially energized at 550V DC situated equidistantly between the running rails. (Important to say that, because the CSLR power rail was also between the running rails but off-set to a non centred position ~384mm left of the right-hand running rail looking towards the City. From the drawings I’ve seen the contact surface of the CSLR conductor rail was about 15mm below running rail level. Corrections welcome). Back to the Central: Although executed between stations with a diameter of 3.562m, tunnels built nearer to stations had a diameter of 3.51m. In stations the positioning of the running rails and platforms placed the former nearer to the wall opposite the platform. This effect of this is discernable at some central London stations. Also, I believe that the widening of the diameter for the curves at both Shepherds Bush and between Bank and Liverpool Street was not as generous as with later lines. Also remember, that CLR stock (loco hauled from the beginning) was shorter than the later ‘standard’ tube stock that had a longer longitudinal secant line on curves and thus overhang. Taken together these factors mean that if the positive conductor rail had been laid at standard height in a 3.51m tunnel (405mm from the inner edge of the adjacent running rail and 76mm above it), there could be less than 36mm between a tunnel ring and the outer edge of that power rail. Standard stock was operated on the 3-rail system to May 1940 and then converted to the LPTB standard being built west of North Acton and east of Liverpool Street. But that meant installing the positive rail between White City and Liverpool Street bat about 38mm over the standard 76mm to give an overall surface height of 114mm above the running rail and thus sufficient air-insulation to prevent inadvertent flashovers.