Vehicle radiation scanner

Scope

Symetrica Ltd engaged us to design a prototype system that would be used to present their radiation scanning technology to potential customers.

The principle for scanning was to use a battery powered pallet truck for the controlled locomotion and low centre of gravity. Suitable standard pallet trucks were found, the critical toppling angle checked and a common interface designed. A detector weighing around 100Kg needed to have its centre adjustable upto 2.5metres above ground level. Height adjustment was achieved with a hand operated winch and high strength Dyneema cord passing through an overhead pulley wheel and onto a vertically sliding frame – rather like a guillotine. Because of this similarity, various safety mechanisms were designed in.

Design

A collapsible frame was designed to allow for easy transportation. An aluminium alloy extrusion system was used for speed of manufacture and reasonable cost. It also allowed for some flexibility as this was a prototype and if changes were required, they could be implemented quickly and easily. Hinging at mid-height with a custom designed de-mountable hinge gave good access when setting up and removing from site. The winch was used to raise and lower the top section by creating a split in the winch cord, reachable from ground level, and passing it through a snatch block on the base and onto a top section mounted lifting arm. This created a very controlled and safe top section raising and lowering operation with the minimum of personnel and equipment.