C 3031
Issue 1


This Instruction gives details of the methods to be employed in marking the positions of buried couplings and buried jointing chambers, plant provided for military purposes is excluded from this Instruction.

Joint Markers
Normally the position of a buried jointing point would be indicated by joint marker placed flush with the surface of the path or road and immediately over the centre of the object to be marked.  A length of 200lb or 400lb galvanised iron wire should be attached to the coupling or chamber and marker.  Strands from scrap stay wire should be used for this purpose.

The different types of joint marker are:-

  1. Markers, Joint, No. 1 for use in carriageways.

  2. Markers, Joint, No. 3 for use in footways.  These are triangular in shape and can be set in the corner or at the edge of a flagstone.

  3. Markers, Joint, No. 4 consist of an elliptical plate bearing the letters G.P.O. and are suitable for attachment to a fence, post or wall to denote to position of a subscribers leading-in pipe.

Marking Posts
Where a joint marker may become an obstruction owing to wear of the surrounding pavement or where it may be covered by subsequently-added layers of macadam etc., the position of the buried jointing point should be indicated by a Post, Marking, No. 2 placed opposite too spot and against a boundary wall or fence.

Each marking post should be fitted with figures to indicate, in feet, the horizontal distance of the joint from the post.

Figures Withdrawn (or omitted) for security reasons
In the interests of security, the distance figures were with-drawn from (or not fitted on) marking posts on trunk and important cable routes.  These figures should be replaced (or fitted) as opportunity occurs, the records made at the time of removal (or omission) being used for the purpose, and preference being given to those routes where the absence of figures is causing most inconvenience and delay.

C 3031
Issue 6, 5.8.66


This Instruction describes the methods of marking the positions of buried couplings, jointing chambers, polythene cable joints, and amplifier points in jointing chambers.  This Instruction not apply to plant provided for military purposes.

Country roads
Buried plant situated along country roads should be marked by using a Post, Marking, No. 2.  The post should be positioned, where possible, with its long face parallel to the line of the track, so that the numerals face the track along a line at right angles to it.  It's position should be chosen with care so that it will not be a source of danger to the public but at the same time it should be readily visible.  Normally a position against a fence or hedge will be found most suitable.

The distance in feet from the post to the point immediately above the plant should be displayed using Figures, Post, Marking, No. 3.  These figures are fitted to the Holder.

Sufficient space has been provided on the holder to permit the inclusion of the joint number or the letters AP as an aid to identification of plant where it is considered desirable.

In situations where a Post, Marking, No. 2 may become concealed by foliage or grass, a Post, Marking, No. 3 shown in Fig. 3 should be used.

With the increasing use by local authorities of power mowing, cases have occurred where machines have been damaged by partially concealed marking posts. The use of alternative markers flush with the ground is not usually practicable and the taller Post, Marking No. 3 can be used with advantage in such situations.

Rural and suburban roads
In rural and suburban roads where marking posts may cause obstruction, the Marker, Joint, No. 10 can be used.

The Marker, Joint, No. 10 should be sited against the fence or kerb line and flush with the surface of the paving.

The arrow-head indented on the marker should indicate the direction to the plant. Numerals should be fitted as described above.  Where the marker is sited immediately over the buried plant, numeral 0 and blanks should be displayed on the marker.

Where buried plant is situated under artificial flagstones a Marker, Joint, No. 3 should be set in the corner of the flagstone which is immediately above the buried plant.  Alternatively, where a grass verge exists alongside the paving, a Marker, Joint, No. 10 may be sited in the verge at the edge of the paving.

Service pipes
Where it is considered necessary to mark the point at which a service pipe passes beneath a boundary wall or fence, a Marker, Joint, No. 4 should be fixed to the wall or fence immediately above the pipe.

Where buried plant exists in the carriageway and it becomes necessary to renew the obsolete carriageway marker (Marker, Joint, No. 1) a Marker, Joint, No. 10 or a Post, Marking, No. 2 or 3 should be used in lieu, as previously described.

Marking of amplifier points
Where Cases, Repeater Equipment, No. 1 are provided in a jointing chamber it may be desirable, when a well-defined address cannot be given, to mark the jointing chamber to facilitate identification under unusual conditions.  In general, such markings will only be required on country roads and the Post, Marking, No... should be used.  The distance to the centre of the jointing chamber cover should be shown and the letters AP replace the joint number on the Holder, Figures, No. 3.

Marker, Joint, No. 1
Drawing dated 1902
Marker, Joint. No. 10
This supersedes the Joint, Marker, No. 1
Marker, Joint, No. 3 Marker, Joint, No. 3
Marker, Joint, No. 4
Introduced in 1938
Marker, Joint, No. 4
Introduced in 1976
Post, Marker No. 2 (left) and No. 3 (right)
No. 2 with GPO insignia introduced in 1914
No. 2 with PO insignia introduced in 1972
No. 2 with BT insignia introduced in 1987
Post, Marker No. 2 (left) and No. 3 (right)
No. 3 introduced in 1954
Total height of No. 2 is 2' 6"
Total height of No. 3 is 3' 6"
Figures, Marker, Post, No. 3
Cable marker
These were used on main trunk cable routes.
In some instances the distance from the marker was obliterated duri8ng the second world war.



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Last revised: July 28, 2020