materials and equipment
ROOFING SYSTEM
An Australian-made roofing system called Triodetic involves simply the fitting of formed steel tubes into ex- truded shaped hubs. The hubs are made of aluminium and contain from six to nine serated slots which lock the
Triodetic roofing lightweight structural tubes in place. Only one bolt is required at each con- nection.
All construction work is carried out from scaffolding and cranes are not required. Suitable for factories, grandstands, warehouses and
and tem- porary structures, the system is de- mountable and is made to close tolerances so that skilled site labour is not necessary.
The makers are George Hudson Pty. Ltd., 1 Bridge Road, Glebe, N.S.W.
DRAWING EQUIPMENT
The Tessograph shading plate, available in the four patterns illustrat- ed, enables designers and draughtsmen to produce shading tints and textured patterns directly on drawings by slip- ping the required plate under the paper and scribbling evenly over the area requiring shading.
Claimed to save considerable time by eliminating the need for painstak- ing cross-hatching work on technical drawings, the four plates provide an economical, reusable method of apply- ing shading tones.
Each Tessograph plate consists of a
Far East BUILDER, February 1971
thin sheet of beige-coloured poly- styrene with an embossed texture on its face, the standard 290- by 200 mm plate size containing a textured area of 250 by 185 mm. Plate DG1 consists of an even pattern of dots, similar to those on coarse-screen newspaper photographic reproduction, and is recommended as a general shading tint for sky effects, fabric or tiles, as well as shadow projections on architectural drawings. DG2 produces an open granular texture for rough shading,
Tessograph shading plate
grass and foliage effects; DG3 creates an interesting linen-fabric effect that works well for fabric wall coverings and for mosaic or tiled areas; and DG4 consists of parallel straight lines, set at 1 mm centres, for cross-hatching work and brickwork or vertical-boarding effects.
In all cases, an overlapping tech- nique can be utilised to give a darker, richer or more complex effect. The dots, for instance, combine to produce a variety of geometric moire effects, while the parallel-line plate enables the user to create a variety of square or diamond chequer patterns which could represent fabric or ornamental grills.
Supplied packed together in an A4-size clear-plastic wallet, the Tesso- graph plates can be cleaned with ordin- ary soapy water. They are suitable for use in connection with freehand tech- niques, no T-squares or set squares being required, and incorporate a series of small crosses around their outer edges to facilitate accurate align- ment for work over large areas.
The makers are Graphel (Bradford) Ltd., 30 Salem Street, Bradford 1, UK.
MEASURING DEVICE
Accurate measurement of distances can be undertaken in the comfort of a car or other suitable vehicle with the aid of a new device which should be particularly useful to civil engineers.
Distances are indicated on a meter mounted inside the vehicle and are
Measuring trailer
measured by a two-wheeled device towed at the rear. The indicator is powered by two 6V torch batteries and is equipped with on/off switch and a reset switch, allowing it to be zeroed at any point so that a series of separate readings can be taken. At the same time the total distance covered is recorded on a meter mounted in the towed trailer unit.
The trailer weighs 28 lb (12,8kg), measures 36in. by 12in. by 12in. (914 by 305 by 305 mm) and runs on two cushioned tyres. It can be quickly mounted behind a vehicle or used manually for recording short, intricate measurements. It has good stability over rough ground and a facility for rapid changeover from imperial to metric measurement.
The makers, The Landlog Com-
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