Ken Hampson (a Series 1 Club member, who served in CD Headquarters Section (Field Cable & Signals sub-section) in Bolton Division from 1959 until wind down in late sixties) wrote:
The various holes and fitments, and why a Hardtop, on your own Recce vehicle 870, may make some sense with a brief description of the role of the Recce detachment.
A Reconnaissance Detachment consisted of 4 vehicles each crewed by four personnel:
1 Party Leader and Navigator
3 Radiac Survey Meter operator
4 Wireless Operator
The vehicles were tasked to head in the direction of a reported Nuclear Blast at H+1 hour or thereabouts. They followed 3 parallel paths with one vehicle in reserve on the centre path. Periodic radiation measurements were taken inside the vehicle and by knowing the Protection Factor (pretty Low!) the outside value could be estimated and sent back to be plotted at Area control for the big picture. The main radio, fitted on a shelf over the offside rear bench seat was of Pye or BCC manufacture using either 155m/cs (MHz now) or 168 m/cs. This provided a rear link (10-20 miles) to a well sited static Area Control (usually in the local Town Hall basement or Signal Office vehicle). The vehicles were not intended to be in contact with each other except through Area Control. This radio could be powered off the vehicle 12v or more usually used portable batteries contained in wooden boxes which fitted across the vehicle behind the bulkhead. These were removed for recharging.
The second radio set if required, was in a wooden box fitted between the two front seats*. This was a 5 channel set in the 96 m/cs frequency band and was intended to work forward to Manpack sets if for any reason a foot recce was necessary. Again 12v supply, vehicle or boxed battery.
I know of no CD vehicles FFR for 24V. The concept was that in an emergency many of the vehicles would be civilian requisitioned and so the radios etc, needed to be fitted with little or no adaptation.
The only CD vehicles intended to have radios fitted were the Recce LR and the Ford Thames Signal Office. The remaining communications being by Field telephone provided by the Field Cable Party.
And I thought that 'Reconnaissance' meant that the vehicle was sent on ahead to scout for the best fish n' chip shop! We're not very hopeful for the health of those whose job it was to drive towards the mushroom cloud until the front bumper started to glow! Knowing how the wind whistles in round the door tops, I don't think 870 would have been particularly radiation-proof!
*Note from GA: This necessitated the passenger seat being moved 2-inches outwards towards the door to allow enough room. The woodwork in the seat cushion was altered to suit, and extra holes drilled in the rear bulkhead to allow the seat back brackets to be moved outwards. Unfortunately this brought it into contact with the triangular strengthening plate at the top of the bulkhead, so the seat back had to be tipped slightly forward into a more upright position than the driver's seat. Small fillets of wood were put in place to support the back in this position.
The East Anglian Film Archive have a 15 minute Home-Office-produced feature film about the work of a Civil Defence Corps Headquarters Unit, filmed in Middlesex. SXF455 (now beautifully resorted by Russell Hearn) appears at 7.50 to demonstrate how a Reconnaissance Unit operated. You can also see SXF731 (a Field Cable Party, with Brockhouse trailer) in action at about 6.05 in. The film can be viewed here.