Ford (crossing) - Description

Description

A ford is a much cheaper form of river-crossing than a bridge but it may become impassable after heavy rain or during flood conditions. A ford is therefore normally only suitable for very minor roads. Most modern fords are shallow enough to be crossed by cars and other wheeled or tracked vehicles (a process known, fittingly, as "fording"). The problem about fords is that they overflow in wet weather.

In New Zealand, however, fords are a normal part of major roads, such as along South Island's main eastcoast State Highway 1. As most inter-city domestic passengers travel by air and as much cargo goes by sea, long distance road traffic is low and fords are thus a practical necessity for crossing seasonal rivers. In dry weather, drivers become aware of a ford by crunching across outwash detritus on the roadway, and a Bailey bridge off the main line of the road to carry emergency traffic during high water.

At localities where the water is shallow enough, but the material on the riverbed will not support heavy vehicles, fords are sometimes improved by the provision of a submerged concrete floor. In such cases a curb is often placed on the downstream side to prevent vehicles slipping off, as growth of algae will often make the slab very slippery. Fords may be also equipped with a post indicating the water depth, so drivers may know if the water is too deep to attempt to cross. Some have an adjacent foot bridge so pedestrians may cross without getting their feet wet.