The following information is gathered from Dennis Publication NS1066

ENGINE: Rolls Royce B81 8 cylinder in line petrol engine, bore 3¾ in (9.525cm), stroke 4½ in (11.430 cm). Full length liners in chrome iron. Develops 197 bhp at 4,000 rpm. Displacement 6.5 litres. Maximum torque 332 lbs/ft at 3,200 rpm. Compression ratio 7.25:1. The exhaust system is arranged to discharge across in front of appliance towards the off-side.

TRANSMISSION: The drive is transmitted through a fluid flywheel to a four speed Rolls Royce heavy duty fully automatic gearbox, the range selector being a small compact lever on the instrument panel. A two speed synchromesh transfer box is fitted in the transmission line and incorporates a full torque power take-off, the transmission to the rear axle and main pump is by exposed propeller shafts with needle roller universal joints supported in a flexibly mounted centre bearing of adequate dimensions.

GEARBOX RATIOS: Top 1:1, 3^rd 1.45:1, 2^nd 2.63:1, 1^st 3.82:1, Aux low 3.82:1:1.4, Reverse 4:1.

FRONT AXLE: Axle beam of robust construction in ‘H’ section, swivel pins are fitted with PTFE faced thrust washers.

REAR AXLE: Weight carrying portion comprised of strong steel fabrication of vertical banjo type. The drive is transmitted by spiral bevel gears of such proportion as to ensure low tooth loading, which are designed to transmit the full torque of engine to the road wheels. The fully floating half shafts are flanged at the outer end and may be removed without disturbing the wheel bearings. Ratio 6.14:1.

BRAKES (DRUM): Of extra heavy capacity for fire service application fitted with anti-fade linings, total lining braking area 479 square inches. Footbrake hydraulically operated with tandem hydrovac assistance. Handbrake operating on rear wheels only through a suitable cable.

SUSPENSION: Short stiff semi-elliptical leaf springs front and rear with telescopic dampers on front axle designed specifically to give riding qualities and anti-roll characteristics required for fire appliances.

FRAME: Pressed steel of ¼ in x 2½ in x 8 in section parallel side-members, of narrow width allowing for deep side lockers and a tight turning circle. Cross-members are of pressed steel top hat section with welded flanges and assembled by fitted bolts. Grouped and indicated lubrication points are provided for all chassis parts. 10 ft 9 in wheelbase is standard for this appliance, and 12 ft 6 in is available for vehicles requiring midship pump and larger locker accommodation. Overall finished vehicle width 7 ft.

FUEL TANK: 33 imperial gallons rectangular fitted under the chassis side-members and fitted with anti-flash filler neck.

STEERING: A 20 in diameter three spoke wheel on recirculatory ball type steering box. Ratio (in centre position) 26.8:1, 6½ turns lock to lock (approx). Turn circle 42 ft (10 ft 9 in WB), 48 ft (12 ft 6 in WB)

WHEELS AND TYRES: Standard wheels 6.00 x 20 with a 5.4 in offset with 8 x 7/8 in studs. Standard tyres up to 9½ tons gross, 7.50 x 20 12 ply permitting a front axle load of 3 tons.

ENGINE COOLING: Pressurised system flat tube radiator water pump circulation controlled by thermostat. A heat exchanger is fitted, piped to the pump and radiator for prolonged pumping, this system also provides for gearbox cooling. An immersion heater is also a standard fitting.

ELECTRICAL EQUIPMENT: Positive earth 12 volt system with heavy duty dynamo, 35 amp capacity. Two 6 volt 185 amp/hr lead acid batteries wired in series. Four headlamps in paired sealed beam units are provided also twin stop and tail lights, fog and reversing light and twin rear reflectors fitted. The instrument panel is illuminated having ignition and lighting switches, tell-tale lights, speedometer with mileage recorder, ammeter, petrol gauge, servo vacuum gauge.

Control arms mounted on the steering column carry horn button and dip switch, electric bell, siren or two-tone horn switches. The self-cancelling trafficator switch is mounted on the cab facia. Powerful electric paired horns are fitted. Plug and socket for battery charging with red warning light in circuit is fitted adjacent to driver’s seat unless other position specified.

ROAD PERFORMANCE: The appliance when loaded to a gross vehicle weight of 7 ton 13 cwt fitted with 7.50 x 20 – 12 ply tyres and rear axle ratio of 6.14:1 is capable of not less than the following minimum performance:

     ACCELERATION

     *  0-30 mph (approx 50 kph) in 10 seconds

     *  0-40 mph (approx 65 kph) in 20 seconds

     *  0-50 mph (approx 80 kph) in 37 seconds

     MAXIMUM SPEED: 60 mph (approx 100 kph)

     *  Stop and start on gradient of 1 in 4. Brake efficiency on dry level road over 60%.

OPTIONAL EXTRAS:

     *  Disc brakes as detailed in Dennis Publication NS1080

     *  AC Alternator

     *  Dennis extricator as detailed in Dennis Publication NS1043

     *  Power Steering

     *  LHD

     *  Automatic lubrication