GPO Vehicles

Make Morris
Model 10cwt Commercial Vehicle Van
Type 10cwt Area Radio Investigation Vehicle, Type 2 (Morris)
Body Builder  
Use Radio Interference Investigation
Registration Number 379 GXF
Fleet Number  
Date of picture 1964

B 1204
Issue 1, 3.3.67

10-cwt. Area Radio Investigation Vehicle, Type 2 (Morris)

1. General
This Instruction describes the 10-cwt. Area Radio Investigation Vehicle, Type 2 (Morris), the conditions of use and scale of provision being set out in B 1200. The vehicle is issued fully equipped with radio test equipment which is described in the Radio series.

2. General description and facilities
A general view of the vehicle is shown above. It is of welded pressed-sheet-metal construction and has windows along each side of the body. It provides facilities for:-

  1. the comprehensive layout of radio test equipment.

  2. a demountable pneumatic mast.

  3. D.F. work.

  4. a business radio aerial.

  5. the charging of the equipment battery from the vehicle generator.

  6. the stowage of small parts.

3. Data summary
Table 1 gives details of dimensions and loading.

Fig. 2
Fig. 3

4. Seating arrangements
A combined passenger/operator seat is provided in addition to the adjustable driver’s seat. This dual purpose seat occupies a fixed position on the near-side, the position being a compromise between consideration of vehicle construction, apparatus layout, passenger comfort and accessibility from the driver’s seat. The seat-back is detachable and can be moved to the near-side (Fig. 2) to give a comfortable operating position. Fig. 3 shows the seating arrangements with the passenger seat back in the travelling position.

5. Pneumatic mast
The vehicle is equipped with a de-mountable light pneumatic mast to support aerial arrays. Fig. 4 shows the mast extended to its full extent - 25ft. - and Fig. 1 shows it fully retracted; access to the mast head is obtained via a roof hatch (Fig. 5). The maximum weight to he placed on top of the mast is 10 lb.

The mast is equipped with a patent system of clamping collars for interlocking the mast sections, to permit its use on direction finding work and to ensure that the mast does not retract due to air leakage when it is used for long periods remote from the vehicle. The mast will remain fully extended for about 1 hour without the use of the clamping collars. A key is provided for adjusting the clamping collars.

The mast itself is positioned so as to ensure that the operator can conveniently reach a handle provided on the mast housing, to orient an aerial array. Air pressure for raising the mast is obtained from a small electrically driven air compressor (par. 24) and is extended to the ma t via a flexible ho e and plug-in coupling. Pressure is released by unplugging the air pressure hose and substituting a pressure release plug and hose; this hose is necessary to discharge any water accumulating in the mast, outside the vehicle. Spring clips mounted on the apparatus cabinet woodwork adjacent to the mast base, serve to stow the hoses and plugs when not in use.

6. Precautions against accidents:-

(a) Always ensure that the mast is fully retracted before driving off.

(b) Disconnect the air supply plug before moving off; a passenger could press the ‘raise mast’ button by accident.

Table 1

Dimensions ft. in. Loading tons cwt. lb.
Overall length 14'  1" Kerb weight 1    3   28
Overall width 5'  2.5" Allowance for personnel 3
Overall height (including pneumatic mast) 8'  1" Pay load

7   40   

Turning circle 36'  0" Gross moving weight 1   13  68

[NOTE:- The various figure depict the prototype vehicle which may differ slightly in appearance from the production models but there are no material functional differences]

Fig. 4

7. Use of the mast remote from the vehicle
A demountable eight section tripod, and a foot pump, are provided (see also par. 16) to allow the mast to be erected remote from the vehicle. The arrangement of the mast and tripod is shown in Fig. 6.

If the mast or its tripod is left erected and unattended, light guy ropes should be used to prevent the assembly from being blown over.

8. Procedure for raising the mast:-

  1. Plug the air supply hose plug into the socket at the base of the mast.

  2. Depress the ‘raise mast’ button mounted on the power control panel, until the mast reaches the required height.

9. Procedure for lowering the mast:-

  1. Unplug the air supply hose plug.

  2. Plug in the air pressure release plug.

  3. Ensure that the mast is fully retracted.

  4. Unplug the air pressure release plug.

10. Procedure for de-mounting the mast:-

  1. Remove any aerial array from the mast head

  2. Ensure that the mast is fully retracted

  3. Unplug the air pressure release plug where this has been used

  4. Remove the securing bolt fastening the base of 5 the mast to the bottom bearing

  5. Lift the mast, complete with top bearing, out over the vehicle roof. It is advisable to have a second man at ground level to receive the mast to prevent accidents

  6. Fit the aerial aperture cover in position.

Fig. 5

11. Aerials
Television aerials appropriate to local channel coverage are carried, the folded arrays with the longer elements being stowed in roof boxes (Fig. 5) and the U.H.F. arrays within the vehicle body (Fig. 7) when not in use. When a man uses the roof hatch to gain access to the aerials, the passenger! operator seat should be in the operating position so that he can stand on and have free access to the small platform immediately to the rear of this seat (Fig. 2). Do not stand on the seat.

12. A business radio aerial (Aerial Units Nos. 17/1 and 17/2) is fitted on the centre line of the vehicle roof near to the rear so that it is easily accessible to a man standing at the rear of the vehicle.
Do not travel unnecessarily with an aerial array on the mast head and he extremely careful of abnormally low head clearances.

13. Apparatus bench
An L-shaped apparatus bench spans the width of the vehicle body to the rear of the operator’s position and extends round the nearside to the rear of the driver’s seat. On the near-side section of this bench and immediately in front of the operating position, is a frame mounted on flexible feet. This frame accommodates a panoramic receiver in a tilting mechanism, and is surmounted by an apparatus shelf. The remainder of the bench area is surmounted by a flexibly-mounted sub-bench top having a grid of recessed apparatus lashing points and fence rails (Fig. 8). There is a similar grid and fence rails on the apparatus shelf above the panoramic receiver position.

Transportable equipment is secured to the spring mounted bench top and apparatus shelf, using elasticated luggage straps in conjunction with the grid of anchor points. This system allows for flexibility of layout in the event of changes in apparatus design, changes in the recommended layout or recourse to approved local variants. The initial standard apparatus layout specified by the Eng. Dept. (WI) can he clearly seen in Fig. 2.

Fig. 6

Fig. 7

14. Use of apparatus within the vehicle
While the uses of radio test equipment to he housed inside the vehicle are described in the various instructions apertaining to radio investigation duties, there are a number of specific precautions to be observed in relation to its use on vehicles. These precautions are:-

(a) Do not drive while wearing earphones

(b) Do not drive holding a microphone or handset

(c) Ensure that the legal requirements for the operation of a television set in a vehicle are scrupulously observed. These are:-

  1. No part of the television screen shall be directly or indirectly visible to the driver while he is in the driving seat.

  2. None of the television set controls, other than the main switch and sound volume control, shall be within the driver’s reach while he is in the driving seat.

  3. A television set must not be used in circumstances and in a position such that it might cause distraction to the driver of any other vehicle on the road.

Fig. 8

15. Power supplies
The main apparatus power supply is derived from a large capacity vehicle battery mounted at the rear of the vehicle. An ac. generator type of vehicle battery charging system has been used to cater for the increased load but, as an additional precaution to ensure that the battery is kept fully charged, local facilities should be provided so that the vehicle battery can be trickle charged in situ overnight.

To supply 240V ac. for operating the radio equipment, a transistorised inverter is provided.

The inverter is powered from the vehicle battery and is switched on via the ignition switch, and its output is connected via change-over relay contacts and fuses to a bank of three 13A socket outlets. The 240V ac. supply may also be used to operate any low power device, such as a soldering iron, but the total power taken from the inverter must not exceed 300 watts.

A 12V d.c. supply from the vehicle battery is available at terminals provided on the power panel. The rechargeable batteries in the various items of radio equipment should be recharged overnight by connecting the equipments to the 13A socket outlets and then connecting a 240V ac. mains supply to the three-pin base-mounted plug which is fitted in the vehicle for this purpose. Connexion of the external mains automatically disconnect the output of the inverter from the 13A sockets. A schematic drawing of the special electrical arrangement is shown in Fig. 9.

16. Stowage of apparatus
The bench mounted apparatus (par. 13) can safely remain on the bench in transit provided the elasticated luggage straps are fitted; an initial supply of straps is supplied with the vehicle but additional straps can be obtained on local purchase and should be entered in the Investigation Officer’s tool list (A 1112). A nest of three drawers and two open compartments, situated below the apparatus bench, are intended for the stowage of suppressor components, small items of apparatus, and small stores. Larger items of equipment, other than those secured to the bench top, can be carried as floor load on the rear floor area, any items susceptible to damage being protected by a mat of sorbo rubber obtained on local purchase.
The sections of aerial tripod and the foot-pump are carried in fitted compartments below the apparatus bench and accessible from the rear of the vehicle (Fig. 7).

17. writing facilities
A pull-out flap situated immediately above the nest of drawers (Fig. 2) is provided for the convenience of the operator when making notes or completing forms.

18. Security arrangements
The rear doors are equipped with an individual barrel lock while the offside cab door is equipped with the standard FP 750 code barrel lock so that the vehicle contents can be safeguarded when the vehicle is left unattended for short periods in the street (the near-side cab door is locked from the inside by turning the door handle in the reverse direction to that for opening the door). For additional security and where the cab has to be accessible to other P.O. staff, the contents of the body can be locked off by means of a reinforced screen which can be erected between cab and body sections and padlocked; the screen is stowed above the near-side wheel arch when not in use.

[NOTE:- Padlocks 1.25 in are sometimes of the self-locking type. To prevent the accidental locking of keys inside the body section, it is recommended that the padlock keys should not all be carried together with the other car keys]

19. Maximum load
The maximum permissible load can be obtained from Table 1, bearing in mind that the weight of an average man has been taken as 168 lb. A simple check can be made by weighing the vehicle in its moving condition, i.e. with the driver, passenger, equipment, petrol, oil, etc. The gross moving weight must not exceed 33 cwt. 68 lb. Any weighbridge charges involved should be passed to ‘Freight and Cartage’.

20. Lighting
The window units provide a reasonable level of natural light in day-time. For night work an internal fluorescent light is mounted on the nearside above the passenger/operator position. This light is controlled by an integral switch.

21. Heating and ventilation
A fresh air type of cab heater/demister is fitted. This can be used to aid ventilation, in conj unction with the openable window quarter lights, in summer. Additionally, in good weather, the roof hatch can be left open while the vehicle is stationary.

22. Provision of fog lamp
See M 0025.

23. Provision of sun visor
See M 0021.

Fig. 10

24. Compressor
The compressor, which is housed in the compartment behind the hinged power panel (see Fig. 10) should be lubricated once a week with a few drops of SAE grade 20 oil. After lubrication the compressor should be run for a few seconds to disperse the residual oil in the flexible hose.

25. Vehicle tools
See M 0011. Vehicle tools should be stowed within the accommodation mentioned in par. 16.

26. Spare wheel
The spare wheel is clamped to the side of the vehicle on the near-side of the rear compartment. It should be cleaned before being replaced after use.

27. Re-enamelling or retouching
The outside of the vehicle has a synthetic enamel finish. Attempts to retouch any scratched or damaged parts should not be made by the staff using the vehicle; work of this nature will be undertaken by the W.Supr./Mech. I/C when necessary and during periodic overhauls.

28. Signwriting
A special format and lettering are used on this vehicle and this special standard must be maintained throughout the life of the vehicle. Publicity posters will not be displayed.

29. Garaging
Lockable accommodation should be provided to safeguard the expensive apparatus normally carried. Where difficulty is experienced in providing such garaging facilities and the vehicle has to be left in the open, all the apparatus should be removed from the vehicle. The overall dimensions of the vehicle are given in Table 1. Care should be taken to allow space for gangways, cleaning, etc., where it is parked with other vehicles, to safeguard it from disfiguring scratches. Its position should be chosen to conform with the requirements of par. 15.

30. Speed limit
See D 0022.


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Last revised: June 27, 2017