Vehicle Specification for Charmichael Mark 12A
I am slowly collecting information about my Carmichael Mark 12A fire engine from a wide variety of sources. This includes the manufacturer and part and equipment providers. Where possible I have acknowledged the provider of the information. Frequently it is the vehicle itself that has provided the raw data. As it is a unique vehicle there is very little published information to which I can refer. However, over time I expect this section to expand and hope that it will become the definitive source of information regarding the Mark 12A. It is the elevating platform that distinguishes it from a normal Mark 12.
I phoned Carmichael in June 2010, and as I found earlier when I needed some parts, they were extraordinarily helpful. The person I had dealt with earlier had retired about eight weeks prior to my call in June. Colin helped by providing dimensions directly off of the desk sized paper drawings. He also read through the hand written workshop journal of the time for any references to my Mark 12A. The information he provided is reproduced below.
Also in June 2010 I managed to locate a manual for the 903 engine. I bought a copy from Cummins, the engine manufacture. Unfortunately it was only available form the USA so the postage was almost as much as the manual. It is still under copyright so I cannot reproduce it here.
To see Scammell Crash Fire Rescue Chassis 6x6 dimensioned drawing, click the link. Opens in a new window. Zoom in for detail.
400 BHP and 500 BHP 6x6 Crash tender
A 6 x 6 rear engined chassis for airfield/cross country use with automatic gearbox and multi plate clutch PTO. There are no operational restrictions on the PTO engagement and by selecting 1st gear and low range in the auxiliary gearbox a slow crawl can be achieved whilst making full use of the fire pump. 400 BHP and 500 BHP engines are available and optional tyre equipment is offered and it is envisaged that this vehicle will operate as a major rescue appliance. The expected water capacity at a GVVV of approximately 26.41 tonne is 10,000 litres for 400 BHP models; and at a GVW of approximately 28.45 tonne ,s 11365 litres for 500 BHP models dependent on fire package.
In the tables below there is a mixture of imperial and metric measurements. The first stated measurement is as the source data with subsequent entries being conversions. This of course means that there is no consistent convention regarding the order of imperial and metric measurements.
Base Vehicle | |
|---|---|
|
Maufacturer |
Carmichael Fire Limited |
|
Model |
Mark 12A |
|
Date of manufacture |
16 March 1990 |
|
Serial Number |
CH 4919 |
|
Chassis manufacturer |
Unipower Vehicles Limited |
|
Unipower were previously Scammell |
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|
Chassis number |
LJ 72395 |
|
Number of axles |
3 |
|
Configuration |
6x6 Rigid |
|
Maximum Weights |
|
|
Front axle |
8130 kg - 8 Ton |
|
Rear axle - 1st |
10160 kg - 10 Ton |
|
Rear axle - 2nd |
10160 kg - 10 Ton |
|
G.V.W. |
28450 kg - 28 Ton |
|
Unladen weight |
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|
Tare |
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Model Code |
SM28C50C47GCCD |
| Current tyres | Michelin X 395/85r20 XZL |
| Environmental Conditions | The vehicle in standard loon will operate at any temperature between -12° and 46" C. At any altitude abowl 3668m the engine is derated by 4% per 306m, |
| Crawl and Pump Mode | At 3000 Pump RPM Crawling Speed is less than 6 KPH in all cases |
Vehicle Dimensions
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|---|---|
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The following length dimensions were provided from the original drawings, Gratefully acknowledged |
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Length |
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From the back of the body excluding the mounting ladder |
3.185m - 124.918 in 10 ft 4 15/16 in |
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From last to centre of front axle. |
4.750m - 186.299 in 15 ft 6 5/16 in |
|
From last to front of bumper |
2.059m - 80.756 in 6 ft 8 12/16 in |
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Total body length |
9.994m - 391.973 in 32 ft 7 31/32 in |
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From the back of the body excluding the mounting ladder |
10.511m - 413.819 in 34 ft 5 13/16 in |
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Height - (laden) to top of monitor |
3.370m - 132.174 in 11 ft 0 3/16 in |
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Height - (laden) to top of; platform (lowered and stowed) |
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Height - (laden) to top of airport light |
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Height - (un-laden) to top of platform (lowered and stowed) |
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Height - (laden) to top of airport light |
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Width |
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Ground clearance |
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Angle of approach |
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Angle of departure |
27 1/2 o |
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Track (at ground) |
F 2.010 R 2.080 |
Engine Auxiliaries | |
|---|---|
|
Alternator |
CAVAC7 Type, 24 volt. 60 amp screened |
| Starter | Delco Remy. 24 volt, flange mounted |
| Air Compressor | Cummins Compact 374, litres/min |
| Corrosion Resistor | Cummins spin-on replaceable element |
| Oil filter | Cummins spin-on replaceable element |
| Fuel Filter | Cummins spin-on replaceable element |
| Cold Start Aid | Fleet Guard 24 volt Semi-Automatic Ether Cold Start Aid |
| Steering Pump | Dowty IP3090 |
Engine Manual
I received a copy of Cummins ‘Operation and Maintenance Manual Automotive Diesel Engines United States and Canada’ on 20th May 2010 direct from Cummins in the States.
My engine is a VTA 903-500. The manual translates this code as:
V = Type of engine
T = Turbocharged
A = Aftercooled
903 = Cubic Inch Displacement
500 = Maximum rated horsepower.
The manual also references the engine as a C.I.D. I assume this is Cubic Inches Displaced and not Compression Ignition Diesel.
Engine displacement is defined as the total volume of air/fuel mixture an engine can draw in during one complete engine cycle; it is normally stated in cubic centimeters, liters or cubic inches. In a piston engine, this is the volume that is swept as the pistons are moved from top dead center to bottom dead center. For conversions reference, 1 Liter = 61.02 cubic inches (C.I.D.). 1 cubic inch = 16 cm³ (C.C.). 1 liter = 1000 cubic centimeters.
The 903 is therefore 14.8 lts.
Engine output (power/unit displacement) is calculated as follows;
With a Hp of 500, (373Kw) this equates to 33.78Hp/lt or 25.19Kw/lt. This is relatively low in today’s terms, which can be 100 to 200hp/lt or 75 to 150Kw/lt.
The manual is 68 pages long and was ordered from Cummins QuickServe Store part number 3379137
On the right are two photos of a similar engine, a V903. This engine was found for sale at jobbersinc, and was at the bottom of the link. Presumably now sold.
http://www.eastmarine.ru/incp/katalog/sierra/oil_filters.pdf
Intake / Exhaust / Cooling / Chassis / Undercarriage / Electrical | |
|---|---|
| Air Cleaner | GKN Farr replaceable paper element, mounted high al the rear of lhe chassis. |
| Exhaust system | 127mm exhaust system with twin silence!l; mounted high at the rear of the chassis. |
| Cooling | The cooling sys(etn is remote mounted from the engine being positioned at the rear of the chassis on the RH side. Twin radiators. total face area 0.83 sq m are cooled by a Wilmot Breedon 813mm fan of the puller type. The fan is driven via a failsafe Dynalr Thermo fan drive unit, to conserve power. |
| Frame | Frame sidemembers are constructed from channel section high yield stress steel to BS 4360 508. The main sidemember section is 309 x 89 x 10mm. Crossmembers are channel section and all bolted construction is used. |
| Front Bumper | A heavy duty channel section front bumper is fitted. |
| Towing | Front and rear towing loops are fitted. |
| Wheels and Tyres | Michelin G20 Pilote on 3 piece disc wheels. Options: 16.00-20 Michelin XL or XS (5.89: 1 Axle ratio) |
| Brakes | Air operated Kirkstall 'S'-cam 394 x 203mm brakes are fitted front and rear An EEC split system is installed. Spring brake units are fitted for parking and secondary braking. A snatch coupling is fitted to the rear. |
| Steering | A ZF 8065 integral power steering box with ram assistance is fitted. It is equipped with hydraulic reaction valves to give superior steering characteristics. |
| Fuel Tank | A 200 Litre fuel tank of pressed and welded steel construction is fitted on the left hand side of the chassis at the r-. The tank is mounted on brackets bolted to the sidemember. |
| Electrical Equipment | A 24-volt system with negative eanh. 4 off 12-Volt maintenance free batteries fitted wired in series parallel Batteries mounted at the rear of the chassis. A battery isolation switch is fitted. Full normal lighting is fitted (head, side, stop. tail, direction indicator, reversing and rear fog lamps). Cold starting capability: - 12° standard - 23" optional. Electrical system screening to enable VHF radio to be used. |
Transmission Specifications | |
|---|---|
| Gearbox | Allison HT 750 DRD automatic transmission providing 5 forward speeds and 1 reverse 1st gear is manually selected and in conjunction with the low range of the auxiliary gearbox enables crawling al less than 6 KPH whilst pumping at 3000 Pump RPM. Gears 2 through 5 are shifted automatically. The gearbox is rated for 373 kW (500 BHP) and 1532 Nm 11130 lbf ft). The transmission includes a three element torque converter, a lock-up clutch and inhibitors to prevent harmful downshifts or reverse shifts. |
| Gear Ratios | 1st; 7.97:1 Manual selection 2nd; 3.19:1 3rd; 2.07:1 4th; 1.40:1 5th; 1.00:1 Reverse; 4.47:1 |
| Torque Converter | Allison TC400 series |
| Engine Power Take Off Openings |
400 BHP Models Standard - 500 BHP Models Optional Number 2 Location One on top, one on left hand side of converter housing at 7 o'clock position (as viewed from output) |
| PTO Openings | Size SAE 8-bolt Rating, Each opening; 194 kW (260 BHP) intermittent, 149 kW (200 BHP) continuous. Rating, Combined; 298 kW (400 BHP) continuous. |
| Propshafts | All Hardy Spicer needle roller shafts, 1710 series fitted between the auxiliary gearbox and the front axle. 1810 series fitted between the auxiliary gearbox and the rear axle, and 1810 series fitted between the main gearbox and the auxiliary gearbox. |
| Front Axle | The driven front axle is a Kirkstall SD65 and is equipped wIth a cross differential lock. Suspension Is by semi-elliptic multi-leaf springs. |
| Axle ratio | 5.36:1 |
| Capacity | 8.13 tonne |
| Maximum Lock | |
| Angles | Front 29.50 Rear 37.50 |
| Turning Circle | Kerb to kerb - 21m - 69ft |
| Rear Bogie | The driven rear axle is a Kirkstall D65 and is equipped with a cross differential lock. Suspension is by semi-elliptic multi-leaf springs. |
| Axle ratio | 5.36: 1 |
| Capacity | 20.32 tonne |
| Power Take Off |
400 BHP Models Standard - 500 BHP Models Optional 500 BHP Models Standard |
| Drive Modulator (Optional on Sandwich PTO) | Available as an alternative is a vehicle/pump drive modulator. This provides. independent control of vehicle or pump drive by incorporating a friction clutch between the sandwich power take off and main transmission. PTO ratio = 1.247 x engine speed. HP rating • 335.7 kW (450 BHP) at 3000 Pump RPM |
| Auxiliary Gearbox | Kirkstall AGB 7000 gear unit, twin speed 1.0:1 and 1.96:1 reduction. Front wheel drive and range change selected by means of air cylinders. When 1.96: 1 ratio Is selected front wheel drive is automatically engaged |
Cab / Controls / Instruments | |
|---|---|
|
Cab |
The steering position is in the centre of the cab surrounded my gauges, switches and lights. The driver’s seat is full suspension which is very good for cross country. |
| Cab | A three man steel cab. which is constructed to enable a crew compartment extension. is fitted. It is untrimmed but includes a full instrument panel, laminated windscreen. side windows, and windscreen wipers/washers. The cab is able to meet impending cab impact legislation. Cab height and noise levels are particularly low due to the rear engine installation. A temporary driving structure is available as an alternative to the cab. |
| Cab |
The two crew seats either side of the driver are designed to accommodate crew in full kit including breathing apparatus. to the Rear seating and hatch |
| Controls | All controls are arranged for use with protective clothing. Centre steer is standard. with options for LH or RH steer. |
| Instrumentation - Instruments | The instruments supplied are: Electric fuel gauge Pressure gauge -hand brake system Pressure gauge -service brake Pressure gauge - auxiliary reservoir Pressure gauge - engine oil Temperature gauge - water Temperature gauge - gearbox Speedometer - MPH Tachometer Ammeter Engine Hour meter |
| Instrumentation - Warning Lights | Handbrake Low Air Alternator Neutral Front Wheel Drive PTO engaged Main Beam Oil Pressure Water Temperature Direction Indicators Rear Fog Front Differential Lock Rear Differential Lock |
| Instrumentation - Switches | Inspection Lamp Sockets Panel Light Switch Hazard Flashers Rear Fog Switch Start Switch Starter Button |
| Instrumentation - Column Mounted Switches | Dip Switch Headlight Flasher Horn Direction Indicators Washers/Wipers Lighting Switch |
| Additional Equipment |  Mast light 110V switch and gauge |
| Additional Equipment |
|
Emergency lights and sirens controls and indicators
Optional Equipment | |
|---|---|
| Kysor Radiator Shutter | |
| Heater and Demister (with cab) | |
| SAB Automatic Slack Adjusters | |
| Automatic Drain Valves | |
| Trickle Charger | |
| Engine Coolant Heater | |
| Engine Sump Heater | |
| Cold Start Aids to -23" C | |
| Spare Wheel | No |
| Service Kit | No |
| Roadside Tool Kit | No |
| Engine Tool Kit | No |
| Wheel Changing Equipment | |
| Tyre inflation Equipment | Yes |
| Smiths Speedometer - KPH | |
| Quartz Halogen Headlamps | |
Vehicle Performance | ||||||
|---|---|---|---|---|---|---|
| GVW Tonne | Maximum Speed -KPM (MPH) | Typical Acceleration Times (Seconds) - 0-80 KPH (0-50 MPH) | Power to weight ratio | |||
| 5.36:1 - G20XL | 5.89:1 - 16.00-20XL | 400 BHP | 500 BHP | 400 BHP | 500 BHP | |
| 22.35 | 112 (70) | 115 (71) | 37.4 | 29.9 | 13.4kW/tonne (18.2 bhp/ton) | 16.7kW/tonne (22.7 bhp/ton) |
| 24.38 | 112 (70) | 115 (71) | 40.8 | 32.6 | 12.3kW/tonne (16.7 bhp/ton) | 15.3kW/tonne (20.0 bhp/ton) |
| 28.41 | 112 (70) | 115 (71) | 44.2 | 35.4 | 11.3kW/tonne (15.4 bhp/ton) | 14.1kW/tonne (19.2 bhp/ton) |
| 28,46 | 112 (70) | 115 (71) | Not applicable | 29.9 | Not applicable | 13.1kW/tonne (17.9 bhp/ton) |
Rather than put a small selection of many photos here, please see the Carmichael Mark 12A galleries below, either by watching the slideshows or following the links. This is a repeat of the gallery about the Mark 12A containted in Mark 12A and TM Purchase and Arrival for ease of reference
Photo galleries powered by SmugMug
To see the photos of post delivery inspection of the Carmichael Mark 12A in HD follow this link to my photo gallery site. Click here.
