Signalling on BVT was going to have to follow QR branch line practices, dually thanks to its there and back style of operation, limited visibility and erratic radio coverage. It was therefore decided that staff and ticket working with trailable facing points and kangaroo points (both of which return to the running road after at train has trailed through) thus insuring that down trains would stick to the down line and up trains would stick to the up line in passing loops.
Trailable Facing Points
The trailable facing points are operated by a spring, the
blade is attached to a piston and line through to a second piston that is filled
with oil. This second piston operates the indicator which shows the blades have
returned to running position. They can only bechanged in the facing direction if the isolated sprung counterweight is unlocked. Two of these are in production at the Ipswich BVT workshop.
blade is attached to a piston and line through to a second piston that is filled
with oil. This second piston operates the indicator which shows the blades have
returned to running position. They can only bechanged in the facing direction if the isolated sprung counterweight is unlocked. Two of these are in production at the Ipswich BVT workshop.
Ground Frames
Also being built are signal/point interlocking levers for the scale station
of Aramac Junction. These levers have been water jet cut to profile and
then machined to the correct upper profiles on the curve. The leavers operate the blade (BLACK LEVER) and the Plunger (BLUE LEVER). The Plunger locks the Points so as not to allow the force of the train pushing on the blade to transfer back to the leaver. These points can not be set trailed through when set against you.
of Aramac Junction. These levers have been water jet cut to profile and
then machined to the correct upper profiles on the curve. The leavers operate the blade (BLACK LEVER) and the Plunger (BLUE LEVER). The Plunger locks the Points so as not to allow the force of the train pushing on the blade to transfer back to the leaver. These points can not be set trailed through when set against you.
Kangaroo Points - The Aussie Odditiy
These Points, as far as I am aware, are a quaint odd-bod of Australian Railways, the idea was to have a easly changed trailable point. To achive this a L shape was made pivoting on the right angle with counter weight on the short end and the long end being used as a handle which when pushed down (in the bad old days sat apon) would direct the train into non main line. This has been modeled at BVT and has proved quite a nice and fuctional touch.
Staff, Ticket and Signals
The BVT operates on a staff and ticket system, best described by John Knowles:
The staff was the authority to occupy a section of single track between the stations marked on it. Those stations were called staff stations, and had a loop line for trains in opposite directions to pass, or in railway terms, to cross or to meet. If the driver of a train carried the staff, he knew that no other train could be on the section, to approach his train from front or rear.
One problem with the ordinary staff was that trains could not follow each other in the same direction without
some means of conveying the staff back to the other end. This was solved by showing the staff to the driver of the first train in one direction, and giving the staff to the driver of the last to go in that direction before a train in the opposite direction could return it. To bring some order into “being shown the staff”, the staff for each section had a head with a designated shape, and the driver of each train which was to proceed without the staff had to carry a ticket. The ticket was obtained from a particular book held in a box, to which the staff was the key, each ticket had details of the train and its time of entry into the section, and each ticket issued had a stub retained in the book which contained the same details. When the staff was in use, the box could not be opened, and tickets could not be issued. Hence the “staff and ticket” system.
That system therefore allowed two (or more) trains to follow one another in the same direction through a staff section. None could come from the opposite direction until the staff carried by the last of these trains, reached the other end of the section. The following of one train by another was sometimes hours apart, but need not be – sometimes two trains wanted to follow one another through a section at a much shorter interval.
This practice is followed but modified to include scale lower quadrant semaphore signals, linked to a staff collector to add additional visual confirmation of a sections clearance, no staff in the collector means that the signal will be set to danger, after the train passes with the staff being dropped into the collector the signal swings back to green.
The staff was the authority to occupy a section of single track between the stations marked on it. Those stations were called staff stations, and had a loop line for trains in opposite directions to pass, or in railway terms, to cross or to meet. If the driver of a train carried the staff, he knew that no other train could be on the section, to approach his train from front or rear.
One problem with the ordinary staff was that trains could not follow each other in the same direction without
some means of conveying the staff back to the other end. This was solved by showing the staff to the driver of the first train in one direction, and giving the staff to the driver of the last to go in that direction before a train in the opposite direction could return it. To bring some order into “being shown the staff”, the staff for each section had a head with a designated shape, and the driver of each train which was to proceed without the staff had to carry a ticket. The ticket was obtained from a particular book held in a box, to which the staff was the key, each ticket had details of the train and its time of entry into the section, and each ticket issued had a stub retained in the book which contained the same details. When the staff was in use, the box could not be opened, and tickets could not be issued. Hence the “staff and ticket” system.
That system therefore allowed two (or more) trains to follow one another in the same direction through a staff section. None could come from the opposite direction until the staff carried by the last of these trains, reached the other end of the section. The following of one train by another was sometimes hours apart, but need not be – sometimes two trains wanted to follow one another through a section at a much shorter interval.
This practice is followed but modified to include scale lower quadrant semaphore signals, linked to a staff collector to add additional visual confirmation of a sections clearance, no staff in the collector means that the signal will be set to danger, after the train passes with the staff being dropped into the collector the signal swings back to green.