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General description and facilities Taken from - ENGINEERING INSTRUCTIONS, TOOLS & TRANSPORT, VEHICLES, N 3021 (Issue 1, 16.8.66) Box Builder's Vehicle Until recently, Areas were equipped with rather inadequate vehicles for Box Building parties. These vehicles were not purpose-built and offered poor accommodation for sand, ballast and tools. A vehicle has been designed to remove these failings, to take advantage of the power tools now available and provide better crew accommodation, which should lead to more efficient operations on jointing chamber construction and maintenance. The vehicle has a two seat cab, behind which is an enclosed compartment for tools and mechanical aids, and has a translucent roof to give maximum light. All the large tools provided are electrically driven, the power being supplied by a propane driven 110V generator. Propane fuel is not so inflammable as petrol so that the generator can be run in this enclosed compartment by using an exhaust extension. The major tools in the vehicle kit are a road breaker, hammer drill, water pump, concrete mixer (carried on rear platform) concrete vibrator, flood lamps, together with all necessary hand tools. Below the enclosed tool compartment on both sides of the vehicle are compartments to accommodate other items, such as red lamps, paraffin cans, propane cylinders, cones reflecting and bags of cement. Clean water is an essential requirement for cement mixing and a 30 gallon tank is provided at the rear of the tool compartment. The rear platform - which has drop sides for easy access - carries storage bins for sand and ballast, skips for the carriage and disposal of spoil, cement mixer, frames and covers, shuttering, etc. For handling heavy items such as frames and covers of approximately 5.5cwt., skips full of spoil approximately 10cwt., an hydraulic powered crane is provided. This has a three section folding jib of one ton maximum load, and can be controlled from both sides of the vehicle. Stabilising jacks are provided either side of the crane mounting to steady the vehicle when the crane is in use. The colour of the vehicle is Traffic Yellow. This is a safety measure, as in course of its work, the vehicle spends much of its time parked at the roadside, or in the carriageway and in dull weather or against dark backgrounds, the bright colour makes the vehicle as conspicuous as possible to other road users. The new Box Building vehicle offers great advances in tool, material, and crew accommodation over the stores carrying vehicle previously used for these jobs. This together with the mechanical aid facilities should lead to more efficient operation of Box Building parties. Some 180 of these vehicles are being obtained most of which have by now been delivered to Telephone Areas.
PO ENGINEERING INSTRUCTIONS Box Building Vehicle Type 1 1 General 2 General Description
Fig .2
Fig. 3 3 Forward Compartment The 2KW generator (Electric, Orange No. 2) fits underneath the bottom shelf close to the doorway. It is run on propane fuel and may be operated inside the compartment using the extension silencer, the power leads being extended to the electrically operated tools as required. The road breaker box is secured to the rails on the rear wall. In order to keep the cement dry and to prevent cement dust from fouling the interior of the compartment, the cement locker (fig.4) has separate access doors on the off side and there is no connection between the locker and the interior of the compartment.
Fig. 4 4. Lockers 5. Security 6. Water Tank Drinking water should be carried separately in Bottles, Polythene, No. 2. In cold weather the tank should be drained each night and on no account should any sort of anti-freeze be put into it. The purpose of the tank is to carry clean water for mixing concrete and mortar. The tank should be filled at the TEC (before commencing each days work) using a hose pipe attached to the water supply. 7. Rear Platform A folding step is fitted to the tail board. The whole of the platform is covered with aluminium tread plate.
Fig. 5 8. Crane
Fig. 6
Fig. 7
Fig. 8 The base of the crane is extended to two stabiliser legs each of which consists of a cylinder with a manually operated piston. Oil is allowed to flow by gravity from the reservoir in the base of the crane via the control valve at the top of the cylinder into the cylinder. When the foot of the piston touches the ground, shutting the valve forms a hydraulically locked support leg. The leg is retracted by opening the valve, raising the leg manually to its full extent by means of the handle, and then closing the valve. The working pressure of the hydraulic system is 1990 psi. The oil pump is driven from a side power take off on the gearbox and is engaged by means of a lever adjacent to the gear lever (Fig 8). A pilot light on the instrument panel indicates when the PTO is engaged (Fig. 9). As first issued the crane was et to lift 1 ton at a radius of 5 feet, but this may be increased to 30 cwt at 5 feet (see para. 12.1).
Fig. 9 9. Crane lifting capacity When modified to the MT Works specification, quoted in Paragraph 12.1 the lift at the full extension of 11' 6" is 12.75 cwt. At a radius if 10' the lift is 15 cwt, at 7' radius 21 cwt and at 5' radius 30 cwt. 10. Lifting tackle
The Three Skips Stacking can be used for sand and ballast to a total quantity of 18 cwts. When empty the skips may be stacked to give more room on the rear platform. By using the skips solely for ballast and sand these materials are kept clean enabling mortar and concrete of good quality to be produced. The two Skips Tipping are for the conveyance of spoil from site. Each holds 10 cwt of spoil. When loaded they should be positioned towards the front of the platform. They may be placed one on top of the other when empty. 11. Operation of the crane 11.1.1 Ensure that the handbrake is firmly on and that the vehicle is safely parked. 11.1.2 On arrival at the site use the rotating amber beacons until all warning signs, cones, etc, have been positioned. The beacons should then be switched off. If, however, it is considered that the situation requires the continuous use of flashing beacons those fixed to the vehicle may be used for short periods by running the engine to avoid discharging the battery. For all other continuous duty Beacons Electric Green numbers 1 or 2 should be employed together with the required battery and/or generator. 11.1.3 The stabiliser legs must be lowered and locked to prevent movement of the chassis under transverse load conditions. On soft ground stout boards should be placed under the stabiliser feet to spread the load. 11.1.4 The operator must make sure that there is no danger of fouling overhead power or telephone lines, street lighting or any other obstruction and also that the crane will not be operated so as to extend beyond the guarded working area where it might constitute a hazard to the public. 11.2 After the crane has been used and stowed in the normal
carrying position, operators
must ensure that:- 11.2.2 The PTO is disengaged before driving away. 11.3.1 The booms are raised from the folded and stored position by moving the top control lever towards the rear of the vehicle. Should this control move towards the front of the vehicle to raise the booms then a modification is required (see para. 12.2). The booms should be raised to approximately 30 degrees above the horizontal as indicated by the small triangular hinged plate, situated on top of the inner boom, just reaching the end of its travel. 11.3.2 Operate the bottom control lever to slew the booms so that they lie in line with the body. 11.3.3 Operate the central lever to raise the outer boom to its maximum extension. 11.3.4. Operate the top lever to lower the inner boom slowly until the outer boom passes the vertical position and falls forward under gravity. 11.3.5 Operate the central lever to lower the outer boom. 11.3.6 Extend the outer boom by removing the "B" clip from the retaining pin, pulling out the extension and refitting the retaining pin and "B" clip. 11.4 Stowing the crane 11.14.1 Retract the manual outer boom extension. 11.14.2 Slew the crane so that the booms lie in line with the vehicle. 11.14..3 Elevate the inner boom to approximately 300 above the horizontal. 11.14.4. Fully extend the outer boom. 11.4.6 Lower the outer boom until it rest on the top of the inner boom. 11.4.7 Slew the booms so that they lie vertically above the stowed position. 11.4.8 Lower the booms into the stowed position. 11.4.9 Retract the stabiliser legs. 11.4.10 Disengage the power 11.5 General notes on the operation of the crane More than one control may be operated at a time as for instance during lowering and slewing. It is not possible to overload the crane as safety valves are incorporated, but it is possible to pick up a load at a short radius and extend the radius to a point where the crane will not sustain the load. In this case the safety valve operates and the load is automatically lowered at a fixed rate but out of the operator's control. The load may be brought under control again by reducing the radius before the load reaches the ground. All staff should stand well clear of the load at all times. The load must never be passed over anyone's head. When lifting a load from the forward end of the platform it may be necessary to use the inner hook first and then transfer to the outer hook, reversing this procedure when loads are to be placed well forward. When lowering a load over the rear of the vehicle care should be taken to fold up the tailboard step, to lower the side board adjacent to the controls in use, and to remove the rear corner post on that side. 12. Modifications
13. Maintenance Maintenance instructions for lorry loader are given in L0025. 14. Testing and Inspection For tests and inspection of the lifting tackle see Routine, Q3030 and Q3031. 15. Use of vehicle 16. Vehicle Tools 17. Fire Extinguisher and First Aid Box 18. Spare wheel 19. Loads The load on the rear platform must not exceed 2.25 tons and should be placed as far forward as possible. This load is also limited by other tools and stores carried and the Total GMW of 7 tons must not be exceeded. 20. Towing capacity 21. Signwriting An extract from The Development of a Box-Building Vehicle A vehicle has been designed to meet the needs of a self-contained party employed on the construction and maintenance of jointing chambers. The final design represents a practical attempt to rationalize the handling methods involved in this class of work. INTRODUCTION The most difficult job which faces the box-builder is the placing of heavy frames and covers, including "unit-type" ones weighing up to 5.5cwt each. This is because the positioning of a frame on a prepared base is a precise operation, and the heavy weight must be lowered to an exact position. In some cases vehicles have been specially adapted, e.g. an overhead longitudinal beam has been fitted on gantries to assist in handling the heavier loads. Two aids to handling have been used: a simple jib and the
gantry with fixed beam. Both these handling aids are very limited in their
application, in that off-loading can be done only from the tailboard and the
area within which a load can be positioned is very small. Furthermore, the
vehicle itself must be precisely positioned with relation to the jointing
chamber, but this is not always possible when the jointing chamber is on the
footpath or grass verge. Similar difficulties are encountered when placing
the shells of cross-connexion PROTOTYPE VEHICLE
The box half-body and open rear platform fulfilled the first two design requirements, while the chain-operated hoist on a traversing beam supported by a gantry fulfilled the third. The body was built by the staff of the Motor Transport Branch, Post Office Engineering Department, on a 4ton forward-control chassis. Racking was fixed in the box compartment to provide adequate accommodation for tools and equipment. The vehicle was equipped with a full complement of 110-volt mechanical aids deriving power from a propane-gas-operated 110-volt 2 kW generator, gas operation being introduced to dispense with the need to carry inflammable fuels inside the tool compartment. Consequently, external lockers were provided to carry the spare propane cylinder, paraffin cans and road-caution lamps. Containers were provided to carry materials so that they might be kept clean (an essential requirement for the production of sound concrete), together with containers, designed for ease of tipping, to be used to dispose of spoil. The mechanical-handling arrangements on the rear platform relied upon a gantry-frame supporting a retractable pin-jointed main beam made up from two 3in. x 1.5in. channel sections, back to back with sufficient space to allow a fixed pin to pass through the retractable beam. The rear end of the beam was suspended from the gantry to which the traversing arrangement was attached. The two small trolleys which made up the traversing gear were operated by means of a wire rope, attached to both ends of the upper trolley, passing down through the framework of the gantry, via pulley wheels, to a worm-and-wheel unit mounted below the rear platform. The actuating rod was operated by means of a cranked handle which could be fitted at either side of the vehicle. The field trial proved that, although the principle of a self-contained gas-operated generator to power the mechanical aids required was successful, the lifting gear was unsuitable. The frame lacked stability, which could only be provided by extra ironwork at high level, but this was undesirable. The traversing mechanism tended to jam and required too much effort from the operator, particularly when the vehicle was sloping because of cambered roads. It was decided, therefore, to improve the handling device and to mechanize its operations completely; a 1ton hydraulic crane was chosen for this purpose. CURRENT BOX-BUILDING VEHICLE The crane is mounted centrally, allowing use over a wide arc. The rear-platform sides and tailboard were made to drop down, and the corner support posts were made removable for ease of loading. The opportunity was taken to try the new safety colour for engineering vehicles: Traffic Yellow to British Standard 368. Handling Aid Three independently-operated control handles are provided on both sides of the vehicle, inter-connected by means of a mechanical linkage. The separate functions are:-
In order to prevent damage to the tool compartment, rotation of the boom is limited to 180 degrees. This enables operations to be carried out to the rear and at both sides of the vehicle. The maximum lifting capacities of the crane are 9cwt at 11ft 6in. radius and 1ton at 5ft radius. Stabilizers Water Tank Containers Towing Facility CONCLUSION
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Last revised: January 26, 2024FM3 |
