GPO Vehicles | |||||||||||||||||
General description and facilities This vehicle is designed for two-man parties employed on box building. The vehicle should be equipped with a 110v generator and electrically operated mechanical aids, i.e. a road breaker, a submersible pump, a cement mixer and a drill. Immediately behind the two-man cab is a lockable compartment to give security to mechanical aids, tools, protective clothing, etc. There is a water tank with a capacity of approximately 27 gallons so that clean water is available for cement and concrete mixing. A hydraulic HIAB crane of 1 ton capacity is fitted between the forward compartment and the rear platform. This crane will lift loads in the range 9 cwt. at 11 ft. 6 in. radius (using the outer hook and the manual extension on the boom.) to 1 ton at 5 ft. radius. Loads in excess of 15 cwt. must be lifted on the inner hook. The removable rear corner posts and drop sides facilitate loading and unloading operations. The load should be placed as far forward on the platform as possible and must not exceed 2 tons; loads exceeding this should be removed in more than one journey. External under slung lockers provide storage for propane cylinders, paraffin containers and road lamps, etc. An air-tight locker built into the off-side of the forward compartment is for the storage of bags of cement. 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 5.5 cwt., skips full of spoil approximately 10 cwt., 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.
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
|
|||||||||||||||||
Last revised: January 26, 2024FM3 | |||||||||||||||||
