Turn- and Transfer Tables

Turntable or transfer table?

A turntable rotates a bridge around a central pivot and is commonly used to reach radial depot tracks or reverse locomotives. A transfer table moves a straight bridge sideways between parallel tracks and is commonly used in workshops and compact storage yards. Both replace a large set of ordinary turnout connections with one movable piece of railway, so only the track aligned with the bridge is physically traversable at any moment.

Any model can be drawn

RailKernel catalogues can contain any manufacturer and model of turntable or transfer table. Their geometry supplies radius, bridge length, number and spacing of positions, connector locations and the dimensions needed for the canvas. You can therefore draw an accurate depot even when RailKernel does not yet know the device’s digital protocol. As with other catalogue items, vendor, catalogue number, image, product page and manual can identify the physical product independently from operational support.

Current operational support

RailKernel offers two ways to control a turntable: a TURNTABLE accessory using the Märklin or YaMoRC YD7652 control type, or direct DCC commands per drawn exit without an accessory. Choose according to the decoder, not just the turntable manufacturer. Transfer tables do not automatically inherit this turntable control.

Place and connect the geometry

Place the table from its catalogue like any other track. Align each surrounding track with the appropriate geometric connector. For a turntable these connectors lie around the pit; for a transfer table they are arranged in opposing parallel rows. A connected connector is automatically considered usable because removing it would break real layout geometry. Unconnected turntable positions can be enabled or disabled manually through Turntable Connections.

Configure exits and track identities

Open the turntable context menu and choose Turntable Connections. Every catalogue connector has a geometric identifier such as T01, while the project can assign the identifier used by the physical installation or decoder. Mark only positions that really exist and can be reached. Clean exit definitions prevent commands to imaginary tracks and make the displayed bridge position meaningful. When track numbering differs between the catalogue drawing and the decoder, this mapping is where those two worlds are reconciled.

Roundhouse sheds

A usable turntable exit can be marked as Shed. RailKernel then draws a radial shed behind that exit, extending it along the connected track geometry where possible. Shed markings describe the depot and make storage roads immediately recognisable; they are not themselves buildings, feedback contacts or automatic parking instructions. Add the surrounding track, blocks, feedbacks and any desired building imagery separately. Automatic “park locomotive in shed” selection is a natural future application of this information, not a current command.

Control through a turntable accessory

For the dedicated Märklin or YaMoRC control, create a TURNTABLE accessory, select its control type, command station and base address, and assign it to the drawn turntable. Accessory Monitor uses the corresponding address mapping. Direct DCC commands per exit require no accessory. The two methods are mutually exclusive: while at least one direct address assignment exists, RailKernel refuses accessory assignment with an explanation. Clear every DCC address field before switching methods.

Calibrate before operating

Calibration tells RailKernel where the physical bridge already is; it does not move it. For a turntable with an accessory, choose Calibrate Turntable and click the geometric connection facing the operator-house end of the bridge. This is separate from mechanical adjustment and track programming in the decoder. After restarting, check that the displayed position agrees with the physical bridge.

Operate the supported turntable

Operation depends on the selected control type. Märklin control provides its rotation, stepping, Stop/Go, lighting and sound functions. For YaMoRC, select the destination track for either end of the bridge. With direct DCC control, click a drawn connection to send its stored address and Red or Green command. Every click repeats that same command; the colour does not toggle. The selected command station must be connected and in GO. An exit without an address sends no direct command.

Bridge feedback, blocks and trains

For a turntable accessory, the inner ring displays the configured Bridge feedback and the outer ring displays Emergency stop feedback. Free uses the configured accessory colour; occupied uses the configured occupied-feedback colour. These reports are separate from train occupancy on the bridge track. Use Feedback Monitor to inspect the received values. If movement stays active while the bridge is stationary, investigate the decoder status and physical turntable.

Use in routes and automatic driving

For a supported turntable with an accessory, the graph uses the saved bridge position when opening the project. Only aligned connections form a path through the bridge. A block and feedback contact on the bridge describe train occupancy; approach tracks retain their own blocks and feedbacks. Direct DCC track selection without an accessory does not itself provide automatic depot routing or a confirmed bridge position.

If the bridge and drawing disagree

• Check which control method you use: Märklin/YaMoRC with an accessory, or direct DCC addresses without one.
• Check the selected command station, GO status, address and red/green command.
• Check the decoder address table and programmed tracks; a turnout address is not necessarily a track number.
• For YaMoRC, compare movement and emergency feedback in Feedback Monitor with the two rings.
• For accessory control, recalibrate if physical and displayed bridge positions differ.
• For direct DCC control, first test the address and colour with an ordinary turnout.
• Check physical bridge alignment and train occupancy before entering the bridge.