Section 13: Permanent Speed Restriction Signs

(Page 4 of 6)

The conventional signs for displaying non-standard differential speed restrictions are based on the standard circular speed sign, with the addition of letters that identify the applicable type of train [13.66]. An elliptical sign can be used in areas of limited clearance or to accommodate speeds composed of three figures, e.g. "100" [13.67]. Unlike some earlier signs applicable only to HSTs (see [13.37 & 13.41]), these signs do not override any subsequent signs indicating a lower speed, and therefore no termination signs (see [13.38 & 13.42]) are needed.

The types of trains to which these signs may apply are identified by the codes below:

• "HST" for High Speed Trains (i.e. Class 253 and 254, and subsequently also to Class 91 locomotives with Mark 4 coaches and to certain classes of multiple unit trains)
• "LH" for Loco-Hauled Trains
• "MU" for Multiple Unit Trains
• "DMU" for Diesel Multiple Unit Trains
• "EMU" for Electric Multiple Unit Trains
• "SP" for 'Sprinters' (applies only to certain classes of DMUs)
• "WES" for Class 442 ('Wessex Electric') EMUs
• "LUL" for London Underground Limited Trains; also applies to other EMUs fitted with tripcock apparatus
• "CS" for Class 67 Locomotives
• "S7" for London Underground Limited S Stock

Generally where these signs are installed, a higher speed applies to the specified type of train indicated, except that a lower speed may apply where "LH", "EMU", "LUL", "CS" or "S7" is shown [13.68]. Class 185 'Desiro' diesel multiple units, introduced in 2006, are not permitted to run at higher speeds shown on "MU" or "DMU" signs. Exceptionally, more than one code may be displayed on a sign [13.69].

[13.66] Non-standard Differential Permanent Speed Restriction Sign. Area: All Areas   Usage: High   Status: Current	[13.67] Non-standard Differential Permanent Speed Restriction Sign. Area: All Areas   Usage: High   Status: Current
[13.68] Non-standard Differential Permanent Speed Restriction Sign (e.g. lower speed applicable to LUL trains). Area: All Areas   Usage: Medium   Status: Current	[13.69] Non-standard Differential Permanent Speed Restriction Sign. Area: St. Pinnock - Largin   Usage: Low   Status: Historical

Exceptionally, a directional arrow may point upwards in addition to one pointing left or right [13.70], to indicate that the speed sign applies to the straight route as well as the diverging route.

[13.70] Permanent Speed Restriction Sign with Directional Arrows applicable to straight route as well as diverging route. Area: Various   Usage: Low   Status: Uncertain

Local variations exist in the signing of non-standard differential PSRs, where the two speeds are combined on a single sign [13.71 - 13.74] or advance warning indicator [13.75 - 13.77].

[13.71] Non-standard Differential Permanent Speed Restriction Sign (combined). Area: Predominantly Western Region   Usage: Medium   Status: Uncertain	[13.72] Non-standard Differential Permanent Speed Restriction Sign (combined). Area: Various   Usage: Low   Status: Uncertain
[13.73] Non-standard Differential Permanent Speed Restriction Sign (combined). Area: Various   Usage: Medium   Status: Uncertain	[13.74] Non-standard Differential Permanent Speed Restriction Sign (combined). Area: Various   Usage: Medium   Status: Uncertain

[13.75] Advance Warning Indicator applicable to a non-standard differential permanent speed restriction (combined). Area: Various   Usage: Medium   Status: Uncertain	[13.76] Advance Warning Indicator applicable to a non-standard differential permanent speed restriction (combined). Area: Various   Usage: Low   Status: Uncertain	[13.77] Advance Warning Indicator applicable to a non-standard differential permanent speed restriction (combined). Area: Various   Usage: Low   Status: Uncertain

One variant type of combined non-standard differential speed restriction sign has the code letters indicating the type of train presented as a suffix after the relevant speed [13.78].

[13.78] Non-standard Differential Permanent Speed Restriction Sign (combined). Area: Various   Usage: Medium   Status: Uncertain

On parts of the Eastern Region (Great Eastern Main Line and branches), a single-letter suffix after the lower figure (higher speed) indicates the type of train to which the restriction applies [13.79 & 13.80]. The suffixes used on these signs are:

• "M" for Multiple Unit Trains
• "D" for Diesel Multiple Unit Trains
• "E" for Electric Multiple Unit Trains

[13.79] Non-standard Differential Permanent Speed Restriction Sign. Area: Great Eastern Main Line   Usage: Medium   Status: Uncertain	[13.80] Non-standard Differential Permanent Speed Restriction Sign. Area: Great Eastern Main Line   Usage: Medium   Status: Uncertain

The hitherto isolated railways of Great Britain were connected with the French rail network upon the opening of the Channel Tunnel in May 1994. This necessitated permissible speed information being presented in both miles per hour (MPH) and kilometres per hour (KMH) for the benefit of continental drivers working international train services into the UK. Signs showing speeds in both imperial and metric units [13.81 - 13.83] were initially provided in the Dollands Moor area, just west of the boundary between British Rail and Eurotunnel infrastructure.

[13.81] Permissible Speed Sign showing imperial and metric speeds. Area: Dollands Moor   Usage: Low   Status: Historical	[13.82] Permissible Speed Sign showing imperial and metric speeds. Area: Dollands Moor   Usage: Medium   Status: Obsolescent	[13.83] Advance Warning Indicator showing imperial and metric speeds. Area: Dollands Moor   Usage: Low   Status: Historical