Home Page > Section 13; pages: 1, 2, 3, 4, 5, 6

Section 13: Permanent Speed Restriction Signs

(Page 2 of 6)


Following a derailment on the curve at Morpeth on 7 May 1969, the British Railways Board agreed to the provision of advance warning indicators on the approach to certain speed restrictions. The new indicators, which first appeared in 1971 and became known as 'Morpeth boards', had yellow figures within a yellow border on a circular black background [13.24]. They were placed at braking distance in rear of the start of the speed restriction and in many cases were floodlit at night. An advance warning indicator applicable to a speed restriction on a diverging route carried an additional directional arrow below [13.25]. A vertical arrow was exhibited below an advance warning indicator that applied to a speed restriction on the straight route beyond a diverging junction [13.26].

[13.24] Advance Warning Indicator. Click Here for Photo
Area: All Areas   Usage: High   Status: Obsolescent
[13.25] Advance Warning Indicator with Directional Arrow (e.g. applicable to right-hand diverging route).
Area: All Areas   Usage: Medium   Status: Obsolescent
[13.26] Advance Warning Indicator with Vertical Arrow.
Area: All Areas   Usage: Medium   Status: Historical

In 1971, a speed restriction of 25 m.p.h. was experimentally imposed on Class 7, 8 and 9 freight trains over the line between New Mills South Junction and Cheadle Junction (London Midland Region). Where a higher speed applied to other classes of trains, this was indicated by the bottom figure of a differential 'cut-out' speed restriction sign erected at the point of commencement [13.27]. Similar signs were installed on the line between Burton-on-Trent and Knighton South Junction in 1972.

[13.27] Differential Permanent Speed Restriction Sign.
Area: London Midland Region (subsequently All Areas)   Usage: High   Status: Obsolescent

The Class 253 & 254 'High Speed Trains' (or 'InterCity 125s') were introduced to British Rail in 1976. Owing to their superior braking performance, they were permitted to travel over specified sections of track at a higher speed than other trains. On the Western Region, a yellow triangle was placed on the posts of speed restriction signs, below the cut-out figures, to denote those places where a variation in the permissible speed for certain classes of trains applied. The triangle pointed up if the variation was higher [13.28] or down if it was lower [13.29]. Neither the permitted speed nor the application of the variation was stated, the details of which were to be found in the relevant Sectional Appendix. The first of these signs were installed in May 1977, marking the start of sections where a different permissible speed applied to HSTs.

[13.28] Differential Permanent Speed Restriction Sign.
Area: Western Region   Usage: Low   Status: Historical
[13.29] Differential Permanent Speed Restriction Sign.
Area: Western Region   Usage: Low   Status: Historical

As a temporary measure, boards were installed on the East Coast Main Line in 1977 at the start and end of each section where HSTs were permitted to run at 125 m.p.h. during daylight hours. The commencement boards were circular with a letter "A" [13.30] and the termination boards were square with a letter "B" [13.31].

[13.30] HST Commencement Board.
Area: York - Darlington   Usage: Low   Status: Historical
[13.31] HST Termination Board.
Area: York - Darlington   Usage: Low   Status: Historical

Signs were installed on the Eastern Region to mark the commencement and termination of higher permissible speeds for HSTs. The commencement sign was an upward-pointing pentagon [13.32] indicating the higher speed at which HSTs may travel. This higher speed applied until a termination sign was reached, this being a downward-pointing pentagon [13.33] indicating the lower speed to which HSTs must revert.

[13.32] Commencement Sign. Click Here for Photo
Area: Eastern Region   Usage: Low   Status: Historical
[13.33] Termination Sign.
Area: Eastern Region   Usage: Low   Status: Historical

Where an advance warning indicator was required on the approach to a permanent speed restriction applicable only to HSTs, it bore the letters "HST" above the speed figure [13.34].

[13.34] Advance Warning Indicator applicable to a permanent speed restriction for HSTs.
Area: All Areas   Usage: Medium   Status: Historical

Where a change of permissible speed occurs within a tunnel, it may be indicated by a permanently illuminated indicator [13.35], for example in the central Liverpool area and on the lines approaching King's Cross station.

[13.35] Illuminated Permanent Speed Restriction Indicator.
Area: Various   Usage: Medium   Status: Uncertain

In 1979, experimental reflectorised permanent speed restriction signs were erected at Metropolitan Junction and Gillingham (Kent). Each sign had black figures on a circular yellow background, surrounded by a black border [13.36] and was therefore of similar appearance to an advance warning indicator (see [13.24]) with the colours reversed.

[13.36] Experimental Permanent Speed Restriction Sign.
Area: Metropolitan Junction / Gillingham   Usage: Low   Status: Historical

The speed signs for HSTs installed on the Scottish Region from 1981 were slightly different from those on the Eastern Region. The commencement sign was square in shape [13.37], while the termination sign was a diagonal board, which displayed just a letter "T" rather than a speed [13.38]. Either sign may be provided in isolation or co-located with an ordinary speed sign. On passing a commencement sign, drivers of HSTs may disregard any ordinary signs indicating a lower speed, including any further signs ahead. Ordinary speed restriction signs indicating a higher speed continue to apply. Higher permissible speeds applicable to diesel multiple unit trains were subsequently indicated by similar signs but with the letters "DMU" or "MU" instead of the letters "HST". Signs displaying only the letters "MU" also apply to HSTs and vice versa. Exceptionally, two sets of letters could appear on the same sign [13.39].

[13.37] Commencement Sign. Click Here for Photo
Area: Scottish Region   Usage: High   Status: Obsolescent
[13.38] Termination Sign. Click Here for Photo
Area: Scottish Region   Usage: High   Status: Obsolescent
[13.39] Termination Sign.
Area: Scottish Region   Usage: Low   Status: Historical

Differential speed restrictions were already in existence in connection with temporary speed restrictions (see Section 14) and at some level crossings (see Section 16) when, c.1982, their use was extended to certain permanent speed restrictions. Where this applies, the P.S.R. sign displays two speeds, one above the other (see [13.27]). Where an advance warning indicator is required, this will also show two speeds [13.40]. This form of differential speed restriction has come to be referred to as a 'standard differential' P.S.R., to distinguish them from those 'non-standard differential' P.S.R.s where the type of train is specified by letters, e.g. "HST".

[13.40] Advance Warning Indicator applicable to a standard differential permanent speed restriction.
Area: All Areas   Usage: Low   Status: Historical

Up to a maximum of three different speeds may be displayed on signs at any one location, i.e.:

A range of experimental reflectorised permanent speed restriction indicator signs [13.41 - 13.44] was put on trial at a site near Bishopbriggs on the Scottish Region in November 1984. One sign was simply a reflectorised version of the existing 'cut-out' design of indicator (see [13.17]). Another was a larger version of the equivalent road sign and similar to the speed signs that were then in use throughout the Tyne & Wear Metro system [13.43].

[13.41] Experimental Permanent Speed Restriction Sign.
Area: Bishopbriggs   Usage: Low   Status: Historical
[13.42] Experimental Permanent Speed Restriction Sign.
Area: Bishopbriggs   Usage: Low   Status: Historical
[13.43] Experimental Permanent Speed Restriction Sign (subsequently adopted as standard).
Area: Bishopbriggs (subsequently All Areas)   Usage: High   Status: Current
[13.44] Experimental Permanent Speed Restriction Sign.
Area: Bishopbriggs   Usage: Low   Status: Historical

In June 1985, two experimental permanent speed restriction indicator signs were placed on a bridge abutment between Ruscombe and Maidenhead (Western Region) for evaluation purposes.