Kiosk No. 1 (K1)

The Kiosk No. 1 (K1) was introduced soon after the former assets of the National Telephone Company (A private Franchise) were nationalised to form Post Office Telephones at the end of 1911.  The NTC had operated a ramshackle selection of different Call Office styles during its 31-year licence period.  A review of these identified the pattern in use in Birmingham as most suitable as the basis of a national kiosk.

However, WW1 intervened and it was not until 1921 that the first Kiosk No.1 was introduced.

This was the first standard British Post Office design and primarily intended for use as an open-air public call office in rural areas, later superseded by the Kiosk No. 3.  It was designed by the Engineering Department of the Post Office.  This was the mark 234 and is pictured to the right.

It was similar in design to the old wooden-box call offices, but was made up from three sections of reinforced concrete and fitted with a wooden door with the two sides and front containing glass panels.  Once the kiosk had been constructed it could then be painted any colour to meet local conditions.

Original drawings show the glazed areas containing 2 or 5 panes of glass.  Both variants could be found around the UK.

Circa mid 1929 the telephone signs and spire bracket were retro-fitted onto most K1's.

The Mark 234 version was produced between 1921 and 1922. 

An initial contract had been placed with Somerville & Company in March 1920 for the supply of 50 kiosks at a price of £35 each - this was reduced to £15 in following years because of demand.  In 1928 the cost had dropped to approximately £13.12.6.

Based on the Mark 234, the Mark 235 also had metal window frames fitted.  Produced between 1922 and 1927.

The Mark 236, produced between 1927 and 1930, had a significant change to the window frames.  It has larger glazed windows on two sides and the door, which made the interior lighter.   In 1928 the sign was removed from the door and the pane divided.

Mark 236 dimensions were:- 10' 0" x 3' 0" x 2' 0".

The number of installations has always been a best guess, but in 2021 the numbers were thought to be around 3,100 of the original form and 1,200 of the Mark 236.

Although the kiosk was quite successful, it was considered that a better design could be found.  Eventually by 1931 the installation of the No. 1 in rural areas was discontinued.

After 1927 the inside and outside were treated with two coats of cream Snowcem or one coat of stipple paint with the window frames and the door painted in BS318C, Red 538.

Diagram - EC1336 (Mark 236)

Uses Hinges, Brass No. 1 on the door (4" x 3").

Click here for backboard layouts pre 1936

An Extract from
Technical Instructions XXXVI
Call Office Installations
Part 3 - Kiosks - 1931


1. Kiosks No. 1, constructed of concrete, were designed primarily for use as open air public call offices in rural areas. They have, however, been superseded for that purpose by Kiosks No. 3 which will become the standard for general use in rural areas when the remaining stock of No. 1 is exhausted. Recovered Kiosks No. 1 which are fit for reissue will continue to be used in rural areas as convenient opportunities offer and as long as the stock lasts they may continue to be supplied to subscribers on rental terms for use in positions where the prevailing conditions would render the up-keep of a wooden cabinet unduly costly and where the location of the kiosk will be such that the public is unlikely to assume it to be a public call office.

2. General Design - Diagram EC1336 illustrates the general design and appearance of the kiosk and gives its principal dimensions. The kiosk will be provided as required with the door hinged on the left or right as viewed from the outside.

3. Advice Notes - The provision, recovery or removal of a kiosk will be covered by the issue of an Advice Note.

4. Transportation - The kiosks are forwarded in sections, packed in wooden cases. The latter are the property of the Department and should be retained for use during the erection of a kiosk, after which they should be returned, without avoidable delay, to the Stores Department, Birmingham Depot, or to the Contractor, according to the source of supply.

5. To economize in the cost of packing eases, a requisition for a kiosk should be prepared and forwarded to the Stores Department immediately Advice Note authority is received, but a note should be inserted in the Remarks column indicating that further advice will be given in regard to the delivery of the kiosk. The Stores Department should be advised that delivery can be accepted when, but not before, the arrangements for internal lighting, if any, have been completed and the date on which the telephone line work will be finished is known definitely.

6. Selection of Sites - The Sectional Engineer should co-operate with the Controller, London Telephone Service or District Manager in the selection of sites for public Kiosks No. 1 (see Wayleave Regulation 485B and T.S.I., Division G, Section G3, paragraph 20) and with the subscriber when a kiosk is to be supplied and erected on rental terms.

7. When the site is being chosen, the following points should receive due consideration.

  1. The door and sides of the kiosk are provided with long windows and, to obtain a maximum advertising value these should, if possible, face the pedestrian traffic. When the site is close to a fence, boundary wall or building, the back of the kiosk should normally be adjacent to the fence, wall or building, but at least six inches there from to-allow of the kiosk being re-painted.

  2. Due regard should be paid to the hinging of the door (left or right) and to the direction of the prevailing wind with a view to placing the kiosk in such a position that the tendency of the wind will be to close the door rather than to open it.

  3. It should be ascertained whether or not the proposed site is over a cellar or other underground compartment and, if necessary, a more suitable site should be chosen, or, alternatively, in view of the weight of the kiosk, adequate precautions should be taken against damage to the underground compartment and kiosk.

  4. When it is proposed to erect a kiosk against a fence or wall, the character of the ground behind the fence or wall should be observed.

  5. Proximity of site to a street lamp with a view to avoiding the need of internal illumination.

  6. When the kiosk is to be served by an underground telephone connexion or when it must be illuminated internally, the site chosen should be as accessible as possible to existing underground telephone and lighting plant which will have to be connected to the kiosk.

In regard to lighting see paragraph 47.

A kiosk should not be erected under a tree on account of the disfiguring effect resulting from the dripping of water on the structure during bad weather.

8. General Description - The kiosk is made up of eight sections, viz:-
1 x Base.
1 x Cornice.
1 x Floor Slab.
1 x Pyramid Top.
2 x Side Panels with glazed windows.
1 x Wooden Door frame and Door with glazed panels.
1 x Back Panel.

9. Erection - The following instructions are issued for guidance in the erection of Kiosks No. 1 and should be adhered to in principle, although local conditions may necessitate departures there from in matters of detail.

10. The back and side panels must not be lifted flat after removal from the packing cases.

11. During unpacking and erection, sacking or similar protective material should be laid on the ground under the corners and edges of the sections to avoid damage.

12. The base and cornice are provided with grooves into which the sides and back are to be fitted and cemented in.

13. All edges, grooves, etc., which are to be cemented must be well wetted before the sections are placed in position.

14. Before the base is placed in position, the site should be made firm and level. On unmade ground of a generally level character an "A" quality concrete foundation, see T.I. XIV, Part 1, Section 3 (1) of a uniform depth of from 4 inches to six inches should be provided to support the base but on pavement the base should be bedded on P.C. mortar and left perfectly level. A concrete foundation of the same description is also necessary to provide a horizontal base when the site chosen is on a slope. The foundation should be sunk into the slope and it should be of uniform depth. When necessary, a channel should also be provided on the upper side of the foundation to deflect rain water from the kiosk.

15. If the kiosk is to be erected on ground having a considerable slope, special consideration should be given to the position of the door in relation to the slope, and where the door would otherwise be considerably higher than the ordinary ground level the depth to which the concrete foundation is sunk into the slope should be sufficient to make the height of the step into the kiosk reasonably moderate.

16. Where it is necessary to provide a concrete foundation, it should be put in before any part of the kiosk is taken to the site. When laid it should be protected from the action of frost, shielded from too rapid drying by exposure to sun or wind and guarded for at least forty-eight hours in order that it may set thoroughly before erection is proceeded with.

17. Earth Connexion - When an Earth connexion is required for the telephone to be fitted in a Kiosk No. 1 and the Earth is to be provided by means of an Earth plate, the plate should be slink beneath or in the immediate vicinity of the kiosk, but, in view of the weight of the kiosk, care should be taken when carrying out this work, to disturb the site on which it will stand as little as possible. Provision in respect of the Earth connexion should be made before the base is prepared, whether by simply levelling the site or by the provision of a concrete foundation. The Earth lead should enter the kiosk by way of one of the leading-in holes for underground connexions in the base of back panel, see paragraphs 37 and 42.

18. The foundation having been prepared, the erection of the sections should be in the following order and in accordance with the subsequent instructions Base; Back Panels; 2 Side Panels; Floor Slab; Door Frame and Door; Cornice; Pyramid Top.

19. Base - Place a piece of timber across the site. Lay the case containing the base on the ground at a distance of twelve inches in front of the site. Remove the top of the case. Raise the case edgeways, remove the floor slab and tilt the case forward until the base can be handled and lowered on to the piece of timber. The base should then be adjusted to its correct position so that the slots provided for telephone and electric light service leads in the later pattern kiosk, see paragraph 42, are adjacent to the back or blank side of the kiosk and the piece of timber should be removed. Portland cement should be filled in all round the base at the ground line, trowelled off and left smooth and clean but this should not be done to bases bedded on P.C. mortar, before the mortar has set.

20. Six small pieces of rubber are supplied with the kiosk and a piece must be placed four inches from each end of each groove in the base in which the back and two sides are to be fitted.

21. Back Panel - Place the case containing the back panel about twelve inches to the rear of the base. Raise the ease on its bottom edge, tilt it forward and carefully lift the panel out. When the panel is upright, it is in a position to be lifted into the appropriate groove in the base.

22. Side panels - Place successively each case containing a side panel about twelve inches in front of the base with the bottom edge parallel to the base front and proceed as directed in paragraph 21.

23. When the two sides and the back panel have been erected, they should be screwed together but the screws should be left slightly loose to admit of a final tightening up.

24. Adjustment - As the width of the grooves allows a certain amount of play, the position of the back and side panels in the base grooves may need slight adjustment.

25. Floor Slab. - The floor slab should next be placed in position. It must lie in a central position, clear all round, with a slight slope towards the door, care being taken to ensure that it will not prevent the door closing properly and, in the case of the later pattern kiosk, see paragraph 42, that the slots provided for telephone and electric light service leads are adjacent to the back or blank panel of the kiosk and register with the corresponding slots in the base.

26. Door - The door frame and door should then be placed in position and the door jambs should be screwed to the side panels. The door, when fixed in position, should be tested to ensure that it swings freely and that the restraining strap and door closing spring function properly.

27. Cementing - Before any further work is done, the interstices between the floor slab and base and the panels inside the kiosk and between the base and panels outside, also the vertical joints between the panels should be filled with cement grout. At the foot of the panels, the grouting should be finished off at the level of the floor slab inside the kiosk and at the level of the base outside. After the vertical joints have been grouted, all the screws should be tightened up and the structure made rigid. When the grout has commenced to set, any excess extruded from the joints as the result of tightening up the screws should be scraped off, the joints being afterwards washed down with a brush, and all the holes in which the screw heads are visible should be stopped with grout, flush with the adjacent surface.

28. The grout must be composed of two parts of clean fine washed sand, and one part of Portland cement by measure.

29. Cornice - The structure is now ready for the erection of the upper sections but, as a preliminary to this further work, a light scaffold about four feet high should be erected round the kiosk. Diagram E.C. No. 1391 shows the arrangement. A bed of thin Portland cement should be placed on the top edge of the back and side panels over which the cornice is to be fitted and a piece of timber on which the cornice can be rested should be placed across the top of the two side panels.

30. Lay the case containing the cornice on the ground twelve inches in front of the scaffolding. Raise the case on its edge, remove the cornice and place it up-side-down with its front edge towards the kiosk. Place one of the larger packing eases in a convenient position in front of the scaffolding and lift the cornice on to the case. Two men standing on the case will then be able to lift the cornice on to the scaffolding whence they will be able to lift it into position on the timber placed across the top of the kiosk. When the correct position for the cornice has been found, the piece of timber can be withdrawn and the cornice lowered into place. Care must be taken to ensure that the narrow architrave over the door is fitted flush against the under side of the cornice and the joint between the top of the panels and the cornice should be grouted.

31. Pyramid Top - The pyramid top should be erected in a similar manner to the cornice but, before it is placed in position, a bed of thin Portland cement should be laid in the cornice grooves. The position of the top can be regulated by a man from the inside of the kiosk.

32. Finally any slight surface cracks in the concrete work should be carefully stopped with neat cement and faced up with grout.

33. Roof sign - The frame-work and enamelled signs comprising the roof sign for a Kiosk No. 1 are separate items obtainable under the respective Rate Book descriptions of "Bracket Sign No. 4" and "Signs, Call Office No. 17." One of the former and four of the latter items are required and make up the complete sign. Details of the items are shown on Drawings 9216 and 9217 which are not reproduced but which can be obtained, if required, on requisition in the usual way. The bracket is secured to the roof by one central bolt. A lead washer is provided to prevent water penetrating into the interior of the kiosk and should be fitted on the outside of the roof with the G.I. washer above it. The distance tube immediately above these washers is made in two portions, one of which is three quarters of an inch in. length. When over-head leading-in is adopted, this three quarter-of-an-inch distance piece should be discarded and a Spindle No. 13 should be fitted in its place.

Two positions for the spindle are available:-

  1. Immediately above the G.I. washer;

  2. Immediately below the scroll work with the 5-inch distance piece between the G.I. washer and the spindle.

Position (a) should always be adopted provided sufficient clearance for the wires can be obtained. The concrete ball provided on the earlier type of Kiosk No. 1 should be discarded and replaced by the roof sign.

34. Maintenance - It will probably be found after the kiosk has been in use for some time, that the woodwork of the door and jambs will swell and prevent the door closing properly. This defect must be attended to immediately by planning the edges of the door to obviate the danger of the wind blowing the door off its hinges.

35. Door Fittings - A standard Kiosk 1 is fitted with Hinges, Brass, No. 1, Spring, Door Closing No. 2 (left or right) and Strap Restraining, Kiosk No. 1, and all existing Kiosks No. 1 have been or should have been standardized in this respect. These fitting should be frequently examined by the workman responsible for the maintenance of the Kiosk to ensure that there is no danger of the door being blown off its hinges due to the spring or strap not functioning properly. When necessary, the spring should be adjusted and attention should be drawn to any stretching of the restraining strap that may require to be rectified. The restraining strap should prevent the door from opening to a greater angle than one of 75 degrees which is equivalent to an opening of 2 feet 7.5 inches, measured from the door jamb to the edge of the door.

36. Leading-in overhead - There are a series of ventilation holes at the top of the back panel. The one on the extreme left of the series viewed from the inside of the kiosk should be used for leading-in telephone wires from overhead distribution. Open wires must be terminated on Insulators No. 16 mounted by means of Spindles No. 13 on the 1/2inch bolt which secures the bracket for the roof signs, see paragraph 33; or, if the pole from which the kiosk is served is immediately adjacent to the kiosk, on the pole itself. From the point of termination covered leading-in wires must be run to the ventilation hole and continued via the protector down the left hand batten behind the wall board to the telephone.

37. Leading-in underground - In the Kiosk No. 1 of the earlier pattern elongated leading-in holes are provided in each bottom corner of the back panel and are available for underground telephone and electric lighting wires or a gas service.

38. In kiosks of the foregoing pattern no provision is made for securing conduit and other fittings with the exception of the wall hoard, and the fixing of wooden plugs locally should be avoided as far as possible. When plugs must be fitted locally, the holes to receive them must be made with drills or Rawlplug tools. Chisels should not be used for this purpose.

39. G.I. conduit 3/4inch must be provided for the protection of telephone and electric, lighting wires serving the kiosk from underground distribution. The conduit must be so bent as to pass through the leading-in holes and lie closely against the hack panel in the angles formed by the hack panel and side panels of the kiosk. It is not necessary to secure the conduit as it will be held in position, in one case by the wall board, see paragraph 40, and in the other by the electric light fittings, provided
such fittings are fixed by Rawlplugs and screws or otherwise secured to the back panel.

40. Conduit for telephone wires must he carried up to a point behind the wall board in the space between the batten, see paragraph 71, and the side panel of the kiosk where it will be held in position by the wall board. After the leads emerge from the conduit, they must be continued up the side of the batten to the protector, if one is fitted, and thence behind the wall board to the telephone, or, if no protector is fitted, across the top of the batten and behind the wall board direct to the telephone.

41. It should be arranged that underground pipes and G.I. conduit connect with each other.

42. In future supplies of Kiosks No. 1, the leading-in holes at the bottom of the back panel will be dispensed with and slots will be provided in the base and floor slab for leading in telephone and electric lighting wires or a gas service from underground distribution. Wooden plugs will also be inserted in the back panel adjacent to each batten in the space between them and in vertical alignment with the holes in the base for fixing saddles to secure G.I. conduit.

43. In addition, wooden plugs will be provided for fixing an electric light time switch to the cornice.

44. In kiosks of the later pattern, finch conduit must be provided, if required, (a) for the protection of electric lighting leads which should enter the kiosk via the right hand slots in the base and floor slab as viewed from the front and be fitted in accordance with the layout indicated on the relevant drawing specified in Circular Power 46, Engineer-in-Chief's Monthly List, June 1930, and (b) for the protection of underground telephone wires which should enter the kiosk via the left hand slots in the base and floor slab as viewed from the front. The latter conduit must be carried up to a point behind the wall board whence, on emerging from the conduit, the wires may be run up the batten to the protector and thence behind the wall board to the telephone, or to the telephone direct, if no protector is fitted.

45. Items to be requisitioned separately - The following stores are required in connexion with the provision of each kiosk and must be requisitioned separately, viz.:-1 x Wall Board 48 inches by 29.75 inches; 1 x Bracket Sign No. 4; 4 x Signs Call Office No. 17; Conduit No. 2A - as required; Conduit Saddles No. 2A - as required.

46. The Bracket Sign No. 4 includes a 4-inch fixing bolt with a spear-head shaped iron finial.

47. Lighting - Details of the lighting arrangements and instructions regarding the maintenance and fittings are given in Circular Power Engineer-in-Chief's Monthly List, June 1930, which deals with the general question of all types of kiosk lighting.

48. Decorative Treatment and Painting. - With the Postmaster-General's approval, the following procedure is laid down to ensure the maintenance of a creditable standard of decoration of cabinets and kiosks.

49. Where the P.O. Engineering Staff includes no skilled painter, the decoration work should normally be carried out by tradesmen painters engaged for the purpose by the Department or under contract, cabinets and kiosks being grouped for this purpose so far as is practicable.

50. When, however, the foregoing procedure would be attended by serious inconvenience or would be unduly costly, the work may be entrusted to P.O. workmen provided that men are available who are competent to do the painting with credit to the department. TI doubt exists as to the competency of the P.O. workmen, outside labour should be employed.

51. When the work is put out to contract, a specification should be prepared in accordance with these instructions.

52. In order to improve the appearance of Kiosk No. 1 all kiosks of. that type should be specially treated as described below. No departure from the new standard decorative and colour scheme now laid down should be agreed to without precedent authority. Any difficulty with the local authority or Wayleave grantor in this respect should be referred to the Engineer-in-Chief (Telephone Section) for instructions.

53. Kiosks No. 1 which have been cement washed must be very thoroughly scratched with a wire brush or rasp. The surface must then be washed down with water only and a scrubbing brush - soap or soda must not be used - and allowed to dry. The concrete surface inside and out must afterwards be coated and stippled with the stipple paint specified in paragraph 67.

54. Kiosks No. 1 which have been well weathered and neither cement washed nor painted need only be dusted down with a sash brush before decoration.

55. Kiosks No. 1 which have been painted need not be redecorated in accordance with the standard now laid down until the others have been dealt with. When such kiosks are redecorated, the painted surface must be washed down merely with water and dried before the stipple paint is applied. To gain experience in stippling painted surfaces, the process may be tried out on the back panels or one of the side panels.

56. The stipple paint is a special composition which has a consistency somewhat greater than that of ordinary paint and which, being quick drying, sets fairly hard within twenty-four hours of being applied and continues to harden with time. The surface to which it is to be applied being dry and free from dust, the stipple should be laid on rather thickly - not painted on - with a flat paint brush which is given a wavy motion as in graining. The material must be applied in this fashion evenly and quickly over an area of one-half to one square yard of surface and must then be stippled with a "Brush, Tar, Short Handle," to give a finish which approximates to a fine or medium fine stone texture.

57. A rougher finish should be given to those portions of the interior surface that are subject to pencilling on the part of the public. To effect this, a longer interval must be allowed to elapse between the application of the material and the stippling. It may also be found necessary to lay on the material somewhat more thickly than is ordinarily necessary.

58. The stippling must be carried out before the painting, a sheet zinc or cardboard guard being used to prevent the stippling paint being splashed on the woodwork, etc.

59. The floor slab should not be treated with the stipple paint.

60. To obviate the discolouring effect of rust from the window frames on the stippled surface near the ground, the metal work must be cleared of rust as much as possible, when a kiosk is redecorated, and the parts must be painted with Paint, Oxide, Red" in advance of the stippling.

61. The effect of rain on a newly stippled surface is slight but noticeable. The stippling treatment should therefore, be started only when the weather is promising for the day. Stippled surfaces can be touched up or given a second treatment but at least four days must be allowed to pass after the initial treatment before this is done.

62. It is very necessary to mix the stipple paint thoroughly before use and frequent stirring during use is essential. Nothing should be added to the stipple paint at any time.

63. Stipple brushes must be cleaned in petrol immediately after use and thoroughly dried before again being used. Several brushes must be available and retained in order that a dry one may be used for each job.

64. The stipple paint is held in stock by the Stores Department in 18lb. containers (drums holding about 1 gallon) and, excluding the surface which will be covered by the wallboard, 14 lbs. should suffice for each kiosk. An endeavour should be made to secure economy in transport charges by requisitioning in bulk the quantities for which use can be reasonably foreseen.

65. A partly used drum must have the surface of the contents covered by a piece of grease-proof paper and the lid must be pressed down thoroughly when supplies are not being obtained from it.

66. The window frames together with the headings and the whole of the woodwork of the door must be painted inside and outside and treated to:- One priming coat; One under coat; One finishing coat of paint; One coat of varnish.

67. The Rate Book descriptions of the material to be used for the decoration of Kiosks No. 1 are given below and supplies can be obtained from the Stores Department.
Paint Kiosks, Stipple
Paint Kiosks, Primer
Paint Kiosks, Undercoat
Paint Kiosks, Finishing, Special Red.
Varnish, Weatherproof.

68. With the exception of the Paint, Stipple, see paragraph 64, the paints specified in the preceding paragraph are stocked by the Stores Department in 1/4pint, 1pint and 1gallon containers, while the varnish is stocked in 1gallon containers. One gallon of each kind of paint should suffice for twenty-four kiosks, but, as the amount of each kind required per kiosk is small, the size of containers and quantities requisitioned should be commensurate with the requirements that can be reasonably foreseen. Supplies of paint or varnish obtained in bulk by the gallon to economize transport charges should be issued from section stock in small containers of not more than 1pint capacity.

69. Redecoration - Great importance is placed upon the advertisement value of kiosks to the Post Office. As, owing to the varying atmospheric conditions to which kiosks are exposed, it is impossible to lay down a definite period for redecoration, arrangements should be made for a periodical inspection by a competent officer. In no circumstances should kiosks be allowed to have a dilapidated appearance.

70. Recoveries of Kiosks No. 1 - The Stores Department must be advised immediately a decision has been reached to recover a Kiosk No. 1, in order that arrangements may be made for the item to be transferred elsewhere and thus to avoid the despatch of another kiosk from the Contractor's works. Upon receipt of the advice the Stores Department will forward a standard set of seven packing cases in which the sections of the recovered kiosk should be stored pending the receipt of disposal instructions.

71. Wallboard - Two battens are provided on the back of the kiosk for fixing a "Wallboard 48 inches by 29.75" inches to which should be fitted the telephone, coin-collecting box and notice frames.

72. Apparatus Layout - The general arrangement of the apparatus and notices should be strictly in accordance with the lay-out plans and conditions specified in T.I. XXXVI, Part I. The apparatus fitted in Kiosks No. 1 other than those equipped with a Box Coin Collecting No. 14, complete, should include a Desk No. 17, the size of which is 9 inches by 7 inches. The desk should be fitted in all the existing Kiosks No. 1 concerned.

Additional Pictures

Kiosk No. 1 Mark 234 Kiosk No. 1 Mark 236

Click here for Irish Kiosk No. 1 Mark 234


Additional Pictures

K1 Mark 234 at Crick Tramway Museum


K1 Mark 236


Mark 235, with experimental roof-sign (January 1925)


Early-form K1 (Mk234/Mk235), pictured in the 1930s with the later additional roof sign


Restored K1 Mark 234 at Avoncroft Museum


Restored K1 Mark 236 at Avoncroft Museum


K1 - Illuminated sign - Probably a field trial that was not adopted
Picture dated 1926


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