A cantilever sheet pile derives its stability from 

Sheet pile:

A sheet pile wall consists of a series of sheet piles driven side by side into the ground, thus forming a continuous vertical wall for the purpose of retaining an earth bank.

They are commonly used for waterfront structures temporary construction and lightweight construction where sub-soil is poor for supporting a retaining wall.

A sheet pile wall may be of three types.

1. Cantilever sheet piling

2. Anchored sheet pilling

3. Braced sheeting.

Certain configurations of sheet pilling are termed as bulkheads or cofferdams. A bulkhead is a sheet pile retaining wall of water front, backed up ground.

A cantilever sheet pile wall or bulkhead derives its stability entirely from the lateral resistance of the soil into which it is driven.

The bulkhead is adequately embedded into the soil below the dredge into so that a driven line of sheeting acts as wide cantilever beam in resisting the lateral earth pressures developed above the dredge line. A cantilever bulkhead is used for moderate height only.