Traffic Signs Manual/Chapter 4/2013/21

by Department of Transport (UK)

21LEVEL CROSSINGS

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21.1 This section gives a brief description of the prescribed traffic signs used at level crossings and tramway crossings. For further guidance, reference should be made to the Office of Rail Regulation’s (ORR) publication "Railway Safety Publication 7, Level Crossings: A guide for managers, designers and operators" published on the ORR website. See also section 3 in Chapter 3.

May be used with diagram 572, 573 or 773

May be used with diagram 572, 573 or 773

May be used with diagram 572, 573 or 773

21.2 Diagram 770 is used on the approach to a railway level crossing which is equipped with gates or barriers. This sign is also used at a tramway crossing if barriers are provided. Diagram 771 is used in advance of open railway level crossings which have neither gates nor barriers. Diagram 772 is used in advance of open tramway crossings which have neither gates nor barriers. These signs should normally be sited at a distance from the crossing related to the 85th percentile speed of approaching vehicles, in accordance with Appendix A. See also paras 21.17 and 21.18 for guidance on the use of countdown markers and signing for queuing traffic.

May be used only in combination with diagram 529, 529.7, 558, 770, 777 or 772.
A distance, an arrow or both may be added

21.3 Diagram 773 should be used in advance of wig-wag signals to diagram 3014 at both railway and tramway level crossings. An arrow may be added to the sign pointing either to the left or to the right. An indication of distance may be added. The sign may be used only in combination with one of the warning signs described above, or with diagram 529, 529.1 or 558 where wig-wag signals are used at an opening bridge, a tunnel or an airfield (see paras 7.3, 7.4, 14.1 and 14.2).

May be used with diagram 602 when used with 778 or 778. 7, or with signals to diagram 3074

21.4 Diagram 774 is used to indicate the location of a level crossing which has no gate or barrier. The same sign is used regardless of the number of tracks and at tramway as well as railway crossings.

May be used with signals to diagram 3074

21.5 Diagram 775 is used at all automatic and open crossings. It should not be used at crossings with manually controlled barriers, nor at those which are user operated, unless specifically authorised in the Level Crossing Order. At automatic crossings, it should be placed on each primary and duplicate primary signal post. At open crossings, it should be mounted on both sides of the road, on or near the post carrying the sign to diagram 774.

May be used with signals to diagram 3074. "TRAIN" may be varied to "TRAM"

21.6 Diagram 776 is used at locally-monitored automatic open crossings on double-track lines, where two trains can arrive in quick succession. The sign should be sited on the left hand side of the road.

May be used with signals to diagram 3074. "TRAIN" may be varied to "TRAM"

21.7 Diagram 777 is used at all automatic crossings on double-track lines. The sign should be placed on or near each duplicate primary road traffic signal.

May be used only in combination with diagram 602

May be used only in combination with diagram 602

21.8 Diagrams 778 and 778.1 are used with the GIVE WAY sign to diagram 602 and not with signals to 3014. Special authorisation (see para 1.5) is required to use diagram 778.1 with the STOP sign to diagram 601.1.

POWER CABLES

May be used only in combination with diagram 780A.

21.9 Diagram 779 warns of a place where a road passes under an electrified overhead power cable. It must always be accompanied by a plate indicating the safe maximum height vehicle that can pass below the cable. These signs are normally associated with overhead electric railway or tramway cables and should be used at all such crossings. Because of the high voltage of certain cables, it is very important to ensure that adequate warning is given even where cable heights are greater than 16'-6" (5.03 m).

These plates may be used only in combination with diagram 779. The height may be varied. The height in metric units may be omitted. In diagram 780.1A the arrow may be reversed or omitted, and the distance maybe varied or omitted

21.10 Supplementary plates 780A, 780.1A and 780, 7A or 780.2,4 780.2A indicate this maximum safe height. The dimension may be varied and should show a height which is at least 2'-0" (600 mm) below the height of the overhead conductor for 25kV systems and 1'-6" (460 mm) for systems on lower voltages. At a crossing where the safe height is below 16’-6” (5.03 m), the height shown on the signs should be at least 1'-9" (530 mm) or 1’-3” (380 mm) respectively below the conductor and a load gauge to diagram 781 erected at the safe height. In calculating the safe height, allowance should be made for the effect of the vertical profile of the carriageway on a road vehicle and its load. While the Regulations permit the omission of the height indication in metric units, this is inadvisable. Table 21-1 indicates the heights to be shown on the signs for different cable heights.

LOAD GAUGE

21.11 The load gauge shown in diagram 781 gives beneath cable in an audible warning when the safe height beneath an overhead power cable is exceeded. It should always be used where the safe height is less than 16'-6" (5.03 m); see also para 21.12. A safe height less than 16'-6" is likely to be encountered only at private crossings. At such locations the gauge should be effective as speeds are low and users familiar with the layout. The gauge is intended for use with power cables and not at low bridges over public highways, where speeds are likely to be higher and drivers less able to respond to the sound of the bells in time, or even to hear them at all from inside closed cabs.

21.12 The load gauge must be mounted on two posts coloured black and white in alternate horizontal bands each band being less than 250 mm nor more than 335 mm deep (Direction 43.) Diagram 779 with supplementary plate 780.2A should be used when a load gauge is installed.

The number and colour of the bells may be varied

'Table 21-1

Lowest hot weather height of contact wires		Height of gauge (diagram 781) and height to be shown on supplementary plate (diagrams 780A, 780.1A and 780.2A) for different overhead line voltages				Signs to be used
		25000 volts		Less than 25000 volts
Imperial	Metric	Imperial	Metric	Imperial	Metric
18-9"	5.71 m	16'-9"	5.1 m	17'-3"	5.2 m	Diagram 779 with 780A or 780.1A
18-6"	5.64m	16'-6"	5.0m	17'-0"	5.1 m
18'-3"	5.56m	–	–	16'-9"	5.1 m
18'-0"	5.49m	–	–	16'-6"	5.0m
18'-3"	5.56m	16'-6"	5.0m	-	-	Load gauge (diagram 781) and diagram 779 with 780.2A
18'-0"	5.49m	16'-3"	4.9m	-	-
17'-9"	5.41 m	16'-0"	4.8m	16'-6"	5.0m
17'-6"	5.33m	15'-9"	4.8m	16'-3"	4.9m
17'-3"	5.26m	15'-6"	4.7m	16'-0"	4.8m
17'-0"	5.18m	15'-3"	4.6m	15'-9"	4.8m
16'-9"	5.10m	15'-0"	4.5m	15'-6"	4.7m
16'-6"	5.03m	14'-9"	4.5m	15'-3"	4.6m

LONG VEHICLES

May be used with diagram 528, 572, 573, 783, 785.7 or 786

"LONG LOW" may be varied to "LARGE OR SLOW".
May be used with diagram 607. 7, 782, 785. 7, 786, 787 or 788'

May be used with diagram 786, 787 or 788. "must phone" may be varied to "must use SOS phone"

May be used with diagram 782 or 783. The telephone number may be varied and "RAILWAY" may be varied to "TRAM Co."

21.13 Diagram 782 is used at crossings where there is a risk of long or low vehicles grounding and causing an obstruction which might not be cleared before the next train arrives at the crossing. It is necessary to consider both the approach profile and the relative levels of the running rails. For guidance on the use of this sign with hump bridges see para 7.1.

21.14 Diagrams 783, 784.1 and 785.1 instruct drivers of long, low, large or slow vehicles to phone to obtain permission before crossing the railway. The smallest size of the sign to diagram 785.1 (25 mm x-height) is intended to be read only by a driver having alighted. A larger size will be required if it is necessary for the sign to be read from a moving vehicle. As non-compliance with the sign to diagram 784.1 could result in an accident or expose a driver to prosecution, it is essential that this group of signs is appropriately sized and properly maintained.

May be used with diagram 782, 783, 784. 7, 787, 788 or 7 028.3. "AT CROSSING" may be omitted. "AND USE PHONE" may be varied to "AND USE SOS PHONE" or "& USE SOS PHONE" The latter should be used only when plating an existing sign (see working drawing P 786)

21.15 Diagram 786 indicates the positions at which a vehicle should wait while the driver telephones before or after crossing the line. A marking to diagram 1028.3 (with no accompanying legend) may be used with the sign (direction 25(1)).

787 Site of telephone
(Alternative types)

788 Direction to telephone (Alternative Types)

The direction of the arrow may be reversed

21.16 Diagrams 787 and 788 are used to indicate the location of the telephone. Diagram 788 is used only where this is not readily apparent.

COUNTDOWN MARKERS

The symbols are reversed when the signs are mounted on the off side

21.17 Countdown markers to diagrams 789, 789.1 and 789.2 may be used to emphasise the approach to a crossing. They are intended to divide into equal lengths the distance between the first marker, with three bars, and the crossing. The first marker should be co-located with the warning sign to diagram 770, 771 or 772 (see para 21.2). Unlike the countdown markers on the approach to a junction, the bars do not represent intervals of 100 yards, as the warning sign will usually be less than 300 yards from the crossing. If the signs are duplicated on the off side of the road, for greater emphasis or to improve visibility, the slope of the bars is reversed.

21.18 Where queues sometimes extend upstream of the crossing warning signs, especially if the end of the queue might be hidden by a bend, queue warning signs might be necessary (see para 20.5).

NEW CROSSINGS

21.19 Diagram 790 is used following alteration of the method of control of a level crossing. In the case of a new installation, "CONTROL" should be omitted. The sign must be removed within three months of the date of completion of the works (direction 37(1)).

SIZES OF LEVEL CROSSING SIGNS

21.20 Guidance on the appropriate sizes for triangular warning signs and supplementary plates can be found in Appendices A and B respectively. Diagrams 774, 775, 777, 783 to 786 and 788 are prescribed in several sizes, the smallest being appropriate where approach speeds do not exceed 30 mph, and the largest where the national speed limit applies. For intermediate approach speeds, sizes should be proportioned accordingly, using the nearest prescribed size.