A railway signal box, built in 1872 on the Shrewsbury and Hereford Joint Line.
Reason for Listing
Marsh Brook Signal Box, erected in 1872 for the Shrewsbury and Hereford Joint Railway, is designated at Grade II for the following principal reasons:
* Rarity: as the best surviving example of a small group of LNWR/GWR Type 1 signal boxes;
* Intactness: despite the loss of its door and some original fenestration, it is externally well-preserved.
From the 1840s, huts or cabins were provided for men operating railway signals. These were often located on raised platforms containing levers to operate the signals and in the early 1860s, the fully glazed signal box, initially raised high on stilts to give a good view down the line, emerged. The interlocking of signals and points, perhaps the most important single advance in rail safety, patented by John Saxby in 1856, was the final step in the evolution of railway signalling into a form recognisable today. Signal boxes were built to a great variety of different designs and sizes to meet traffic needs by signalling contractors and the railway companies themselves.
Signal box numbers peaked at around 12,000-13,000 for Great Britain just prior to the First World War and successive economies in working led to large reductions in their numbers from the 1920s onwards. British Railways inherited around 10,000 in 1948 and numbers dwindled rapidly to about 4000 by 1970. In 2012, about 750 remained in use; it was anticipated that most would be rendered redundant over the next decade.
Marsh Brook signal box was built in 1872 for the Shrewsbury and Hereford Joint Railway, a line mutually owned by the London and North Western Railway (LNWR) and Great Western Railway (GWR). It operated under the control of a Joint Lines Engineer's Office which, acting independently of the railway companies, established its own designs and practices for its signalling and signal boxes. Although the design of Marsh Brook is similar to the early Saxby and Farmer brick-built boxes, it was built with a greater depth to give the signalman more room to work in. In 1890 the LNWR took over the responsibility for the signalling and subsequently replaced the original lever frame, possibly manufactured by Saxby and Farmer, with a Tumbler locking frame. In the early-C21 the operating room windows on the south-east elevation were replaced with uPVC windows.
MATERIALS: it is of Flemish bond brick with stone dressings and a Welsh slate roof.
PLAN: a LNWR/GWR Type 1 box which is rectangular on plan.
EXTERIOR: the signal box is of two storeys, with a stone string course separating the first floor operating room from the locking room below. The operating room has continuous glazing to the south-west (trackside) elevation and to the front half of the returns; the window openings all with stone surrounds. The trackside fenestration is divided into three sections by stone mullions and contains a central casement window of three-over-three lights flanked by horizontal sliding sashes of eight lights. To the left-hand return there is an horizontal sliding sash of twelve lights. The right-hand return has an horizontal sliding sash of two large lights, to the right of which is an half-glazed door; both being early-C21, uPVC replacements. Access to the operating floor is via a short flight of wooden steps. The south-west elevation of the locking room has two segmental-headed windows with cross casements. An identical window exists in the left-hand return whilst the right-hand return contains a segmental-headed doorway. Above the string course, fixed just below the operating room windows, is a Shrewsbury and Hereford Joint Railway name board reading 'MARSH BROOK'.
INTERIOR: it retains a lever frame of 18 levers, probably installed in the late C19.
Listed building text is © Crown Copyright. Reproduced under licence.