Specification for Aerial Ladder Platform-(ALP)


1.0 scope:

This specification covers an aerial platform unit with a working height of ~ 42m. The design of operational stability, structural strength shall be in accordance with relevant international standards and norms available on the subject. The ALP shall be CEN (Central European norms and standards) certified and company must be ISO 9001 compliant.

1.1 Chassis:

The chassis on which the hydraulic platform is to be mounted shall be of a Internationally repute make such as Mercedes, VOLVO etc. The chassis shall be of 6 X 4 configuration and shall meet the pollution norms of EURO –II category. The vehicle shall be right hand drive fitted with power steering. The engine shall have sufficient power to achieve a top speed of 90 kmph with an acceleration of 0 to 60 km within 40 sec. PTO for driving the hydraulic pump shall, be a standard feature.

2.0 Main operating data:

a. Working height ~ 42.0 m

b. Height to working cage bottom ~ 40.0 m

c. Working outreach (with 400 Kg) ~ 22.0 m

d. Working reach below the ground level (with 400kg) 6.0 m

e. Safe working load 400 kg

f. Rotation, continuous 360°

g. Transport height < 3.95m

h. Transport length < 11.8m

i. Transport width < 2.5 m

j. Maximum wind velocity 14.0 m/s

k. Maximum width with outriggers extended 5.5 m

l. Elevation angle of main boom from 0º to 80º

m. Operative rate

  1  Maximum working height from gallows/resting – 90 sec similarly depression at the same rate.

  2 Turning through complete circle – 150 sec.

  3 Time to extend jacks on both side – 30 sec.

3.0 Main frame:

The main frame shall be a fully welded rectangular steel structure fixed on to the chassis frame with bolts and springs so as to allow performance and durability of the chassis without causing stress concentration in the chassis beam.

4.0 stabilizing system:

The system shall consist of four outriggers mounted in their housing in the main-frame and are hydraulically powered. Adjustable guides in the housing shall be fitted to provide accurate and smooth movement of outrigger beams. The outrigger beams shall be completely closed by steel profile enclosing hydraulic cylinder, hydraulic hoses etc. The vertical jacks shall be fitted with self-aligning footplates so as to distribute the load evenly. The system shall also incorporate use of “ONE SIDED” mode enabling left or right side outriggers only to be extended where as the outriggers on the opposite side remain within the width of the vehicle. The arrangement shall provide full working range on the fully supported side of the vehicle. The entire system shall also incorporate independent and automatically operating safety devices to prevent an unsafe position to be reached.

Controls for stabilizing system shall be placed in a dust and water proof enclosure at a suitable location with control arranged in such a way that outriggers are always visible to the operator while operating. This enclosure shall also contain control switches such as:

i) Chassis engine starting ad stopping.

ii) Hydraulic pressure activation.

iii) Visual indication for fully extended left outriggers / right outriggers/ rear axle locking (if incorporated)/ main current on/ leveling of vehicle ( longitudinal and transversal).

iv) Operating hour meter.

v) Indication for fault finding system.

vi) Battery driven back up for hydraulic system.

vii) Engagement of P.T.O.

The enclosure shall have proper lighting for night operation.

5.0 bodywork and equipment locker:

The frame shall be made of aluminum covered with non-slip aluminum plates strong enough to allow free movement of persons on it.

Recessed steps shall be provided on both side of vehicle for gaining access from ground level. At least two lockers with roller shutters shall be provided on each side along with automatic switches for activating light within the locker when the lockers are open. There shall also be a warning indication in driver’s cab that the doors are not fully closed. One of the lockers shall house petrol driven engine of stand by system where as the other lockers shall be used for stowage of fire fighting accessories.

6.0. booms:

The aerial ladder platform shall have two/three booms system. The booms shall be made of high tensile strength steel. The first boom may have telescopic extensions. The 2nd boom shall have vertical movement of 180º. The elevation and lowering of main boom shall be achieved by two hydraulic cylinders, both having their separate safety devices and capable of carrying the entire load alone. Adjustable guides shall be provided for smooth and accurate movement and all telescopic section shall be synchronized so as to avoid inter mediate jerks. The booms shall be primed and painted for long life span both internally as well as externally. All movements shall be electro hydraulically servo controlled at optional speed from both the control panels by means of joysticks. When not in operation all control levers will be automatically in neutral position.

7.0 Turntable:

It shall be a fully integrated steel structure fastened to main frame. It shall have a center post containing slip rings with double pins for electrical connections, 100 mm stainless steel water way and hydraulic pressure lines allowing continuous rotation of the turntable. The lower control station shall be located on left hand side of the turn table where as the rescue ladder shall be on right hand side. Rotation reduction gear with automatically operating braking system shall be installed at the front of the turntable. In order to have high reliability, the hydraulic motor powering the rotation shall be directly connected to the gears.

8.0 Working cage:

The working cage shall be made of tubular steel profile, welded construction, having dimensions as - length 1.0 m, width 2.0 m, height 1.1 m. This shall be fixed to the booms providing highest possible degree of natural safety. The cage shall be fitted with two doors. The safe working load shall not be less than 400 kgs. when no water is discharged from the monitor and not less than 200 kgs with monitor in operation.

The working cage shall be kept leveled horizontally w.r.t. any position of the booms. The leveling movement shall be powered by hydraulic cylinder within the boom. The cage shall be capable of being turned 45º on either side from the center position. The movement shall be powered by hydraulic cylinder having control both at cage and turn table. Visual indication for center position of the cage shall also be incorporated at both control panels. A rescue platform with approx. dimension 1.4 m × 0.45 m and safety railing shall be fixed at the front of the working cage. A fully transistorized talk back intercom system shall be fitted between turntable and the cage. Combined microphone and loudspeaker with hand free operation shall be located in the cage where as the main station shall consist of a loudspeaker and a microphone. Provision for audible warning/ signal shall be incorporated when one of the two positions enters in contact with other one. The entire cage shall be covered with non-slip aluminum plates with drain holes.

9.0 rescue ladder:

A telescopic rescue ladder forming a direct and continuous rescue way with no cross- over platform shall be attached on to the R.H.S. of the booms. The extension movement of this ladder shall automatically synchronized with telescopic movement of 1st boom. Both the control panels shall be fitted with visual indication for “ SAFE TO CLIMB” position of the ladder.

10.0 hydraulic system:

A heavy duty variable displacement hydraulic piston pump driven by vehicle power take off shall provide the required hydraulic power. On movement of any operation, the control valve shall automatically increase the pressure to a required level so that the hydraulic oil in required quantity flows in the system for that particular movement. Simultaneously operating several movements, the flow of oil increases automatically as per the system needs. The system shall be designed so as to prevent overloading. The entire system shall be capable of giving the required pressure and flow while the prime mover is running at the best economic and efficiency range. The system shall incorporate a hydraulic oil tank in the main frame having level gauge, temperature gauge, suction connection, drain plug. Oil filters at suction and return lines and pressure filters in each pressure circuit shall be provided. The capacity of the hydraulic oil tank shall be 350 Lts. The main pressure lines shall be fitted with instant coupling and manometer shall be fitted as standard equipment. The hydraulic cylinder shall be double action heavy duty with hard crome plated piston rods with self align ball bearing to prevent lateral forces.

10.1 back up system for hydraulic:

A gasoline engine driven hydraulic pump mounted in one of the lockers shall provide an independent hydraulic power back up in case of failure of vehicle engine. The system shall be capable of starting from both control panels. In addition, a battery driven 24V DC stand by pump as back up system shall also be incorporated to allow all the booms and outriggers movements to be operated for housing purposes in the event of failure of all other systems.

11. Electrical system:

The electrical system shall be 24 v DC from the chassis battery that are kept charged when the engine is running. All electrical circuit shall be provided with fuses. Output sockets for battery supply power shall be provided at turntable and cage.

While main current is switched on, yellow flashing warning lights mounted on outriggers, underneath the working cage and booms shall be automatically switched on. Amber colour rotating beacons on each side of driver’s cab roof shall be provided. The switching controls shall be in the drive’s cab.

11.1 Siren and public address system:

The electrical siren unit shall be fitted behind the front grill the control panel for the operation of the system shall be in the drivers cab. The sound system shall be fast (yelp), slow (wail) and two tone (Hi-low) sounds. The PA system shall have an over riding facility and the microphone shall be fitted with push to talk switch. Time circuit for change of cycle during auto mode shall be incorporated.

12.0 Turn table and cage control panel:

Control panels shall be provided at the turntable as well as at the cage. A convenient sitting arrangement for the operator shall be provided at turn- table. Both the panels shall be exactly similar to avoid confusion whereas the change over switch for selecting the place of operation shall be at the turntable control. both the panels shall be fitted with under mentioned warning/ indications/ control devices. These shall be clearly marked for easy recognition.

i) Audio cum visual warning for exceeding safe working load.

ii) Audio cum visual warning for collision guard system of working cage.

iii) Visual indication for fully extended outriggers (left and right separate)

iv) Visual indication for “Safe to climb” position of rescue ladder.

v) Start and stop of chassis engine.

vi) Switch for gasoline driven and battery driven back up for hydraulic systems.

vii) Control for cage slewing.

viii) Joystick lever for each movement.

ix) Emergency stop switch.

x) Manual operation for working cage-leveling system.

xi) Visual indication for control position of booms and working cage.

12.1 indicators and control in driver’s cab:

The following indicators and control shall be incorporated in driver’s cab:

i) Visual warning for switching on of main current.

ii) Visual warning for booms and outriggers not in traveling position.

iii) Visual indication for any of the locker not in closed position.

iv) Visual indication for engagement of P.T.O.


I) To prevent the booms, cage, outriggers from retracting in case of any hose or pipe failure. All load bearing hydraulic cylinder shall have lock valves.

II) The booms shall be prevented from lifting from traveling position until the outriggers have been extended.

III) Retracting of any of outriggers shall be automatically prevented once booms are lifted from their traveling position.

IV) Movement of all booms shall be limited to their extreme so that the operator cannot attain an unsafe configuration.

V) All movements which directly influence the stability shall be protected by main as well as back up safety system in such a way that the first one stopping a particular movement and 2nd one deactivating the whole hydraulic and electrical system in case of failure of 1st system.

VI) Device for preventing the chassis engine from starting from either of control panel unless the gear is shifted to neutral.

VII) Slow down devices shall be fitted to provide smooth deceleration.

VIII) Audio and visual warning in case of safe working load being exceeded.

IX) System for preventing lowering of Ist boom and rotation movement when the boom is near the drivers cab.

X) Collision guard for cage.

XI) Emergency stop switch on both control panels for freezing all systems.

XII) R.P.M. regulation switch of vehicle engine at main control panel.

XIII) Bleed down system at both the controls for lowering booms and working cage in case of failure of hydraulic system. In such and case, provision of manual rotation is provided.

14.0 water way:

A 80 mm diameter water way made of stainless steel throughout shall be provided with three way inlet having 63 mm male instantaneous coupling with closing valve at the rear of the vehicle. The line leads through the center post in the turntable up to working cage. All along the boom the piping shall be fitted at R.H.S. at protected position between rescue ladder and the boom. The continuous rotation shall be provided even when the water supply is simultaneously used. Relief valves shall be incorporated for protection against overpressure. All along the boom the water pipe shall be telescopic. At boom joints there shall be fixed an access pipe connected by a flexible rein-forced pressure hose using snap lock connections. The piping shall terminate at side of the front cage where a water monitor shall be placed. An additional outlet of 2½ “ female instantaneous outlet along with closing valve shall be provided so that water supply from cage can be used by using an extension hose. Drain cock shall be fitted at suitable locations. Underneath the cage water spray nozzle shall be fitted to provide water curtain to prevent cage occupants from the radiant heat. Control valves for this shall be located inside the cage. All couplings at inlet and outlet shall be in accordance with relevant Indian standards.

14.1 Water monitor:

Water monitor made of light alloy fitted with jet/fog nozzle having a nominal capacity of 3000 lpm shall be connected on to the water piping system and placed at front of the cage just outside the railing. The monitor shall be capable of normal control from cage and platform and also having a provision of remote control. Main isolating valve shall be provided for isolating the monitor.

15.0 Breathing air system:

A breathing air system shall be provided from turntable to working cage. At the cage, there shall be a four way manifold with instantaneous coupling to connect four breathing masks. Air cylinders to supply air shall be mounted at the turntable level. The cylinder capacity shall be such that they provide approx. 9000 liters of free air. Isolation valve shall be provided at suitable location so that the cylinders can be changed without interrupting the air supply. Pressure regulator as required shall also be incorporated into the system. 04 number of suitable facemask shall be supplied.

16.0 stretcher carrier:

Provision for stretcher carrier shall be made at the working cage. The carrier shall be provided in such a way that whole cage area is still available free to its occupant.

17.0 fog lights:

Two fog lights shall be mounted at front bumpers or other suitable locations and controls provided in the driver’s cabin.

18.0 painting:

Surfaces of steel structure shall be sand blasted, primed before painting and painted to a film thickness of 100 microns. All booms shall be primed from inside also. The paint used shall be as under:

a. Working cage - white aluminum.

b. working cage support, booms sections, turntable, cylinders etc. - white

c. Main frame, outriggers, body work - red

19.0 wireless camera:

A detachable and self-contained battery powered video camera with zoom and focus facility shall be mounted at a suitable position in the cage. A colour monitor shall be mounted at the turntable and a colour monitor with recorder in the driver’s cab. The transmission of picture from camera at the cage to the monitors shall be through radio signals. The system shall be capable of switching on and off from the cabin, Camera and the monitor shall have a waterproof design. All functions of camera shall also be capable of being operated from the turntable also.

20.0 graphic display for turn table and cage control station:

A graphic display unit shall be installed at the turntable and at working cage. This unit shall inform the operator about the actual position of the cage and display information’s as per under:-

a. Real cage floor height / maximum cage floor height.

b. Real outreach at cage border/ maximum outreach at cage border.

c. Real angle of main boom.

d. Real angle of tip boom.

e. Warning signal for cage overload.

21.0 communication equipment:

One number of programmable two way VHF mobile radio complete with antenna, microphone and speaker preferably Motorola GM-340 make shall be installed in drivers cab. This shall operate from vehicles battery. Two numbers of walkie– talkie VHF sets Motorola – GP 140 make complete with antenna, battery charger and a spare battery shall be provided.

22. Accessories:

The following shall be provided:-

i) 4 pc Wooden outrigger ground pads with bracket

ii) 2 pc Working range diagrams, one at the turntable, one in the working cage

iii) 2 set Operation and maintenance manuals

iv) 1 pc Plug for 24 v working light at the turntable and in the cage.

v) 1 pc 24 v/ 70 w working light with universal bracket

vi) 1 pc Lifting loop under the working cage, capacity 400 kg.

vii) 2 sets Fitment for safety belts in the working cage.

viii) 1 pc Hydraulic pressure gauge.

ix) 4 pc Locking pins for the outriggers

x) 1 pc stretcher

xi) 1 nos. Microprocessor based fault location with display facilities for the ALP shall be installed at suitable location.


23.1 During manufacture and especially prior to shipment/ dispatch, verification and checks shall be carried out in order to ensure that the supply is according to the specifications and approved design documents. This shall be carried out at Contractor’s premises by a team of three persons to be nominated by the purchaser. The checks shall include:

 a) a functional check of all equipments,

 b)  check of a vital dimensions as per designs

 c)  check on assemblies, welds, screws etc.,

 d)  a check of operation of safety and protection devices

All expenses in this regard shall be borne out by the supplier.

23.2 AT SITE:

After delivery at site, the operating tests shall be carried out at site in presence of representatives of a Contractor to check that the equipment fulfils the requirements of the specifications these shall include all tests carried out in the factory as well as additional tests with actual use.

24.0 TOOLS:

Tools kits shall be supplied along with the supply for all the equipment and machines as per manufacturer’s recommendations



Prior to manufacture of the component, a Contractor shall send the following documents for approval :

 1) General drawings, detailed assembly drawings and detailed drawings of mechanical parts,

 2) Descriptive and operating note, 

 3) Documents, drawings, notes and references of the Sub- Contractors 

 4) Details of the provisions concerning personnel safety and use of apparatus in hazardous areas.


The Contractor shall provide up to date documentation including :

1) The list of general drawings and detailed rawings of electrical and electronic diagrams with complete nomenclature.

2) General nomenclature of supply including the sub-contractors

3) List of mechanical and electrical parts illustrated and itemized in accordance with the diagrams and drawing mentioned above and including the addresses of various contractors.

4) Maintenance manual with details of maintenance schedules and repair procedure for important equipment, summary of circuits, functions and adjustments and a lubrication manual including location of lubricating points, type of lubricants, frequencies and quantities. 

5) An operating manual with instructions for starts up and users instructions

6) Complete documentation of equipments from sub-contractor

7) Spare part list with quantities for five years after handover of the ALP, anticipated frequency of replacement and prices with a one-year validity period.

8) Instructional plates (in English) shall be provided for all controls.


(i) Offshore Training:

The supplier shall provide the training for 5 working days to 4 personnel to be nominated by the purchaser on the operations and Maintenance of the ALP at the manufacturer’s site, preferably, on the same ALP that is to be supplied. All expenses in this regard shall be borne out by the supplier.

(ii) Training in India:

Training shall also provided by the Supplier to 10 personnel in India after the installation, testing and commissioning the equipment in India in Delhi.

Last Update Date :- 04-05-2018

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