Caisson Units (Milshaft)
Reinforced manhole units suitable for sinking by the caisson method manufactured to BS 5911-200 and carry the BS Kitemark where appropriate.
Components (2400-3000 diameter)
- A nominal 1.0m base shaft ring composed of a 12mm overbreak concrete cutting shoe and a standard 0.5m deep shaft unit.
- Chamber sections in 0.5 and 1.0m depths
- Jointing plates
- Butyl rubber joint sealant
- Lifting Brackets
- Landing slab 1.0m deep shaft ring
- Landing slab in two halves
- Landing slab support angle cleats
- Cover slab
The 4.0m caisson is manufactured in two halves and has a separate steel cutting shoe. Components 2, 3, 4, 5, 6, 7, 8 & 9 as above. The cover slab is supplied in two halves.
| Nominal Diameter (mm) | Weight of Base Unit & Cutting Shoe (kg) | Wall Thickness (mm) | Chamber Weight/m Depth (kg) |
|---|---|---|---|
| 2400 | 2440 | 130 | 2560 |
| 2700 | 3040 | 140 | 3060 |
| 3000 | 3800 | 160 | 3810 |
| 4000 | - | 200 | 3220 per half ring |
Landing Slabs
| Nominal Diameter (mm) | Access Size (mm) | Thickness (mm) | Approx Weight (kg) |
|---|---|---|---|
| 2700 | 900 | 150 | 2100 |
| 3000 | 900 | 150 | 2600 |
| 4000 | 900 | 165 | 2680 per half slab |
Full or half landing slabs are available.
Cover Slabs
| Nominal Diameter (mm) | Access Size (mm) | Weight (kg) |
|---|---|---|
| 2400 | *750x600 | 2228 |
| 2700 | *750x600 | 3068 |
| 3000 | *750x600 | 4242 |
| 4000 | *750x600 | 9900 |
*These sizes are to provide a 600 x 600 access when used in combination with a Type 1 and one or two Type 2 cover frame seating rings depth of make up. Other sizes of access are available to order.