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GOOD LIN THE PHON
Page 146
Page 147
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Lloyd Pryse knows a bit about GRP mouldings with 30 years' experience he has been able to develop the sort of lightweight bodies that keep British Telecom coming back for more.
• "We don't really think of ourselves as bodybuilders," says Lloyd Pryse, managing director of Anglian GRP Developments. That's an understandable view: Pryse's background in the glassfibre-reinforced plastics business goes back nearly 30 years.
In his time Pryse has developed and produced mouldings for Lotus cars; for East Coast boat-builders and for Anglian Windows, where he was involved in the development of a double-skinned GRP door.
It was not until 1982, after he had set up on his own in Great Yarmouth, that his vast knowledge of GRP mouldings was tapped by British Telecom (as it was to become), when Pryse was asked to submit a design for a telephone kiosk. The extent to which BT would later figure in the fortunes of his new company could not have been envisaged.
He did not give commercial vehicle bodywork much thought until 1983, when the Eastern Electricity Board in Norfolk came to him to repair the GRP roofs of some demountable bodies. They were transferred from chassis to chassis by being lifted from the top, imposing stresses and flexures which the roofs would not accept.
RIGID MOULDING
Those repairs were successful, but they inspired Pryse to approach EEB with a new body design, made entirely of GRP, with its outer shell produced effectively as a single rigid moulding. It took a year to design and develop the prototype, which was structurally successful, but led to no major orders.
The breakthrough came when Jim Donald, a fleet engineer responsible for body procurement at the newly privatised British Telecom. expressed an interest. At the time BT was buying mainly Sherpa chassis-cabs, with the box bodies built from Glasonit or Dawnpress GRP-faced plywood panels.
While they were tough and durable, these bodies were also relatively expensive and heavy. It was impossible to get the unladen weight of a Sherpa 200Series box made to BT specification down below the 1,525kg HGV-testing threshold. Another minor shortcoming came, ironically, from the toughness of the sidewalls — if a top front corner hit something like a low tree branch the stresses were transmitted back through the body mountings, sometimes causing chassis distortion.
Pryse suggested an all-GRP body based on his EEB design, but further refined in the light of BT's experience and its need for lightness. Late in 1985 an initial tentative order was placed. In May 1986 an order followed for 250 bodies.
Suddenly the company needed much
more factory space. Starting from a 56m2 "shed" in Yarmouth, it moved to a 230m2 factory in Norwich, followed by a 600m2 base elsewhere in the city. Finally Anglian GRP moved to its present site, in the village of Neatishead, not far from the Norfolk Broads holiday resort of Horning. It started life as a granary which has been modernised and extended to 1,440m2 of floor area, on a 1.2ha (three acre) site. The current workforce is 21 people.
Production is geared to one product for one customer: a 2,650mm-long. 1,880mm-wide, 1,930mm-high demountable (and as such selfsupporting) body with a single 600mmwide central rear door, for British Telecom's line maintenance/repair teams. The bodies are all mounted on Ford Transit 120 short-wheelbase (LCX) chassis-cabs.
FIRST GLANCE
Dominating the Anglian GRP plant are seven identical complete-body models, which at first glance look like the bodies produced inside them. This is not surprising because, as Pryse explains, the moulds are GRP mouldings themselves, stoutly reinforced on the outside by ribs which maintain the stiffness, and hence the flatness, of the walls and floor.
Preparation of the mould interior before each lay-up includes polishing the surface and applying a release agent. Then comes a double thickness of gelcoat, coloured BT yellow to give a solid layer of colour more than lmm thick which is resistant to minor scuffing and scratches.
Pryse keeps a close eye on the advances in chemical and physical properties of laminate mouldings. Anglian GRP now uses a "low styrene" polyester resin for its main mouldings. This provides greater strength but is less effective as a bonding agent: to compensate for this an epoxy-based "paste" called Perrnabond is used to join components most notably the outer shell to the pre-moulded inner skin panels.
From the outside, five horizontal "flutes" between rave and cantrail are visible. They appear as ribs from the inside of course, and make up the 9mm air gap in the middle of the sandwich construction. Vertical timber stiffeners are also moulded into the panels between the ribs.
British Telecom's specification
includes a series of rails on the inside of the body, on to which shelves and storage bins can be attached. J-section alloy extrusions are bonded to the inner skin panels before the panels are positioned. A detail modification made early on was to incorporate a wedge-section rib into the inner skin moulding to give each J-rail positive vertical support, rather than relying on adhesive alone. On the offside BT specifies a locker in the bottom rear corner, to house a butane gas cylinder feeding an auxiliary heater. This locker is moulded as an integral part of the inner sidewall: access is via one of the two hatches in the fixed rear structure alongside the main door. The hatch covers and door itself are also doubleskinned GRP structures moulded at Neatishead.
SINGLE-MINDED
Pryse expects to produce 1,200 bodies for BT next year. He attributes his success in a field where others have failed to a single-minded dedication to GRP moulding technology. Bodybuilding in metal or faced-plywood panels is, he readily admits, a closed book to him.
He sees the double-skin principle for all panels, including the 9mm plywoodcored floor, as the key to structural integrity. That means rigidity and durability, but with the ability to "intercept" impact loads before they reach the chassis. BT has set up repair teams equipped to deal in the field with damage to its Anglian GRP bodies using straightforward hand lay-up methods.
When CMB visited Anglian GRP early in October a mould was being prepared for a slightly bigger (3,100mm-long. 2,105mm-wide) body to suit a longwheelbase (LCY) Transit chassis, in response to an enquiry from Telecom Cables. Next year Pryse plans a 3,800mm-long body for the 7.5-tonne market.
by Alan Bunting