THE SIGNAL BOX

OVERSEAS

MULLINGAR
Iarnród Éireann

(former Midland Great Western Railway)

by Simon Lowe

Mullingar signal box
Photograph by Simon Lowe, 3/5/00

Mullingar signal cabin (formerly 'Mullingar No.1' or 'Mullingar East') was built by the Midland Great Western Railway in 1920. The cabin is situated on the station platform, in the vee of the divergence of the routes west to Athlone and Sligo. The former route, via Moate, now has no regular traffic.

One does not often see signals attached to signal boxes, but here at Mullingar you can. Number 35 signal, the elevated disc at the north-east corner of the cabin, applies to the Down Branch. Most shunting signals on Irish Rail have square faces, so to see a true disc signal such as this is quite a rarity. The circular type tends to have been used where a signal was elevated.

Interior of Mullingar box
Photograph by Simon Lowe, 3/5/00

The operating floor of the cabin is accessed via an internal staircase, affording visitors a view of the mechanical interlocking on the way up. The locking has recently undergone an overhaul as part of a programme across the Irish Rail network. The lever frame at Mullingar is one of the longest in Ireland, being of 65 levers. It was made by the Railway Signal Company. Notice the brass-cased repeater above the frame at the left hand end.

Signal box diagram at Mullingar
Photograph by Simon Lowe, 3/5/00

A modicum of track circuiting exists at Mullingar, although not extending over the complex pointwork in the junction area, which includes a single and double slip. Each track circuit is indicated by a separate indicator on the block bench rather than by lights on the diagram. Outside, some of the signal posts carry diamond signs as per British practice, but they are not represented here on the signalman's diagram.

Electric Train Staff instruments at Mullingar
Photograph by Simon Lowe, 3/5/00

Each of the three single line sections from Mullingar is worked by a miniature ETS instrument. All three are seen here, along with the associated magneto hand generator. The keys in the attachments protruding to the right of each instrument are unlocked when a staff is withdrawn. They are then inserted into a lock on the starting signal lever to release it. Normally this feature is indicated on diagrams by the letters 'SSC' for 'Starting Signal Control' alongside the signal concerned, although this is not the case at Mullingar.

Photograph of lock on lever 58
Photograph by Simon Lowe, 3/5/00

A close up view of the SSC lock fitted to lever 58 which controls the starting signal towards Mostrim on the Sligo line. In addition, a catch handle contact can be seen to the immediate left of the lever, indicating that there is some electrical locking down below.

Base of former West cabin at Mullingar
Photograph by Simon Lowe, 3/5/00

A short distance along the main line towards Athlone, the lower half of the former Mullingar West cabin is still standing on the Down side of the line.



Comments about this article should be addressed to Simon Lowe