The roll consists of nine plans detailing a gas float to be commissioned for the Humber Conservancy Board for use on the Humber:

1. J. 2150 B Fittings for A.G.A. [Actylene Gas] Accumulators (Scale: 1 inch to 1 foot [1:12]

2. J. 2150 C Fittings for CO2 Accumulators (Scale: 1 inch to 1 foot [1:12])

3. J. 2150 D A.G.A. CO2 Bell Structure Details (Scale: 1:8). Drawing No. 6840)

4. J. 2150 E Chair of A.G.A. CO2 Bell striking Mechanism (Scale: 1:2). Drawing No. 6841

5. J. 2150 F Arrangement for CO2 Piping for A.G.A. CO2 Bell Unit (Scale: 1:8). Drawing No. 6842

6. J. 2150 I Arrangement of A.G.A. CO2 Automatic Bell (Scale: 1:24). Drawing No. 6842.

7. J. 2172 A General Arrangement (Scale: ½ inch to 1 foot [1:24]

8. J. 2172 B Arrangement for fixing CO2 bell unit under lantern superstructure (Scale: 1½ inch to 1 foot [1:8])

9. J. 2172 E ½ inch lines and offsets (Richard Dunston Limited.

Max Dimensions: 850 x 995mm

The eight sheet includes a print of the signature of Ralph John Hindmarsh, Engineer to the Humber Conservancy Board.