The same container can run on two different castors in two facilities, because tread material, diameter and noise are read together off the same surface. The wheeled version of the GEBHARDT Isotec container comes with Ø125 mm swivel and fixed castors, and threshold and joint dimensions are assessed against that diameter.
| Tread | What it gives | What it costs |
|---|---|---|
| Soft (rubber, soft polyurethane) | Quiet running, floor protected | Higher push and rolling resistance |
| Hard (nylon, hard polyurethane) | Low rolling resistance | Noise, more strain on the floor |
The tread should be softer than the floor, otherwise the wheel presses into the surface and damages it. As diameter grows, rolling resistance falls and thresholds and joints are easier to cross; in return the body rides higher and reaching into the container gets harder. In a hospital corridor, on a hotel floor or during night deliveries, the rhythmic sound of a hard tread over tile joints is heard louder than expected in an enclosed space.
Capacity is worked out per castor: the weight of the container and the maximum load is divided by the number of supporting castors, and the result is multiplied by a safety factor for the conditions of use. Before deciding, run a full container once over the hardest floor and threshold on the route; where it catches or makes noise is something a catalogue does not show.
