Minimise

A correspondent suggested that the superior riding qualities of the latter were due to the absence of piston-valve chests above the cylinders, which made it possible to bring the underside of the water-tanks to a lower level than that of the "Rivers", so minimising the unsteadying effect of water surging in the tanks.

Other requirements in similar vein are to minimise and mitigate the effects of airport expansion on existing surface access and to take all reasonable steps to minimise such effects during construction and operation.

The project was attractive because of the ability to maximise the use of existing and decommissioned railways, minimise land take, and decrease the amount of disruption during the project. With London land prices rocketing, there was also a significant financial incentive.