I'm trying to find out how stretcher bars on double slips were connected to either a point lever or to point rodding.  I have drawings of how the stretcher bars are connected to the switch rails.  But were the stretchers at one end of the slip connected together and then to the point lever/ rodding or were they driven separately or what?  Principally interested in pre-grouping LSWR and LNWR but any prototype information would be appreciated.

Regards,

Ian Spalding

Ian Spalding wrote: I'm trying to find out how stretcher bars on double slips were connected to either a point lever or to point rodding.  I have drawings of how the stretcher bars are connected to the switch rails.  But were the stretchers at one end of the slip connected together and then to the point lever/ rodding or were they driven separately or what?  Principally interested in pre-grouping LSWR and LNWR but any prototype information would be appreciated.

Regards,

Ian Spalding
Partly answered my own question by looking around the Templot site and finding a drawing of a 1:7 GER double slip posted by Martin on 29/07/2009.  Here the two stretchers at one end have separate point rods.  What date was the drawing?  At least it's a start.  Any other information?

Regards,

Ian Spalding

Hi Ian,

In most cases both sets of blades at one end of a double slip are linked and work together. This is always* the case when they are rodded from a signal box and part of the interlocking.

This is convenient in a model because the drive working all 4 blades can also be used to switch the crossing polarity at the opposite end of the slip.

Sometimes in yards where they are worked by hand levers they may have separate levers for each set of blades -- this makes the levers easier to work, of course.

In some designs of double slip it is not physically possible to drive them separately because there is insufficient room between the wing rails to have both blades open simultaneously.

*I can't believe I wrote "always", but I honestly don't know of any case of an interlocked slip with separate drives. But someone will.

regards,

Martin.

Hi All

Had a look at the weedstrewn Woking (ex SR /LSWR) down yard Friday and confirm all the double slips there are indeed worked by two handlevers, and a single tie bar for both sets of blades

Some of these are still worked as part if the yard is for handling of stone/aggregate trains and for the stabling of track machines.

Cheers

Phil Chudley


Martin Wynne wrote:
Hi Ian,

In most cases both sets of blades at one end of a double slip are linked and work together. This is always* the case when they are rodded from a signal box and part of the interlocking.

This is convenient in a model because the drive working all 4 blades can also be used to switch the crossing polarity at the opposite end of the slip.

Sometimes in yards where they are worked by hand levers they may have separate levers for each set of blades -- this makes the levers easier to work, of course.

In some designs of double slip it is not physically possible to drive them separately because there is insufficient room between the wing rails to have both blades open simultaneously.

*I can't believe I wrote "always", but I honestly don't know of any case of an interlocked slip with separate drives. But someone will.

regards,

Martin.