Dennis N-Type

The "N-Type" chassis was constructed from rolled steel channel; riveted and braced at appropriate points.

This was more complex to build than the long-established piston pumps, but had advantages in operation.

Piston pumps also gave a pulsating outlet pressure which required an air-filled receiver to even this out.

A drawback of the usual centrifugal design was the considerable axial force generated by the pump impeller, requiring a thrust bearing.

The chassis was generally fitted with engines by White and Poppe of Coventry.