Building and Developing a Traverser
Bob Hordern
Pictures by the author
It is now over seven years since I began work on
Kirtley Bridge. Right from the start it was clear that I
needed to have storage sidings at one end of my layout,
from which trains could emerge and later return. There
were three basic options available: a train turntable, a
sector plate or a traverser. The first two of these would
have been difficult to manage as my quarry scene, which
hides the sidings, takes up almost half of the width of the
baseboard, restricting the rotation of any table. A traverser
therefore seemed the obvious candidate.
The base of my traverser is a piece of 9mm MDF fitted with aluminium angle to prevent warping. This creates a table of approximately 1005 x 400mm, allowing me to squeeze in five sidings, although they are quite closely placed.
Construction of the sub-
baseboard, showing a
draw runner and tape
‘slider’
To enable the table to move back and forth I have fitted two sliding drawer runners in a horizontal plane. Additionally, there are two sliders of polyethylene tape to reduce any friction between the table and the sub- baseboard. This arrangement copes well with the weight of five O gauge locos and their attached rolling stock.
To align the traverser tracks with the exit line from the layout I chose to use a brass barrel bolt sliding into some cheap housings (below). The latter were then drilled out to create a more accurate fit. Initially this bolt also carried DC current to the tracks on the traverser.
To allow locos to run around, the far end of the traverser has a small headshunt track. This arrangement ran well for home use but the rigours of exhibition working soon found it out. In particular, track alignment at the headshunt end was not always reliable and some derailments did occur.
The alignment problem at the headshunt end
The traverser loaded at the start of day
To rectify this problem, I decided to retrofit the table to reduce this wayward movement. My solution was to use an adjustable door-catch with a simple DIY mechanism.
First, I cut off one end of the fixing plate. Next, I cut a slot through the baseboard to create clearance beside the headshunt. I then secured the table edge with a half inch aluminium angle facing upwards, adjusted the ball and press catch firmly down into the slot, and then tested that it slid satisfactorily.
I fixed half-inch PVC angle, this time facing downwards, over the aluminium angle. I had planned to use a single piece but in the end it was easier to build this up in sections, adjusting the spacing and gluing each as I went along. This created the four detent slots to catch the roller ball. The final frame shows the completed set with the ball finally adjusted. The ball catch housing is clamped not glued down, so that it can be re-set or replaced if need be, and tested.
The two photos above show my 2P running from the headshunt back onto the traverser table. The beauty of this is that the alignment is now done by the ball and slots, ie it operates itself. All I have to do is set the 'active' end of the table with my locking bolt and wait for the reassuring click of the ball catch at the other. Now that the track is DCC, the whole table and the headshunt plank are live, not just the selected siding as was the case in DC. This means that the operator’s actions are much more secure. The alignment bolt reverts to being a locking mechanism and is no longer needed as a power link.
More recently the table has had a further upgrade, this time designed to improve running properties on and off the traverser. Here I have fitted guides (lozenges) within the tracks to prevent derailments and insets to enable re- railing. All of these items are made up of varying thicknesses of plastic card. The newly added guides and insets take better care of rolling stock. (Readers may be interested in seeing the traverser in action by viewing the website: https://youtu.be/WLXNBFJrHiI).
From the public point of view all of this is action well hidden behind the quarry scene, at the front of the layout. Most visitors never get to see the traverser properly, unless of course they ask! The last baseboard on the layout is quite complex, housing both Hebden Beck Quarry and the traverser, all in the space of 4ft by 3ft.
The newly added guides
and insets take better care
of rolling stock
