Precast Concrete Caisson Rings & Caisson Shaft Units
Precast Concrete Caisson Rings & Caisson Shaft Units
FP McCann manufactures a full range of precast concrete caisson rings suitable for shaft sinking by the caisson method. Caisson shaft units are available in nominal diameters from DN2100 up to DN4000, in ring depths of 500mm, 750mm and 1000mm, with light-duty or medium-duty cutting shoes available on base units.
Caisson rings are manufactured within the scope of our ISO 9001 accredited Quality Management System and in accordance with BS EN 1917 and BS 5911-3 where applicable. Manufactured in the UK, with nationwide delivery and technical support from design through to installation.
What are caisson rings?
Caisson rings are reinforced precast concrete rings stacked and bolted together to form a shaft that is sunk progressively into the ground — either under its own self-weight or with the aid of caisson jacks — in a controlled manner from the surface to a predetermined depth. A metal cutter ring and base section are installed first, with further rings added on top as excavation proceeds beneath them.
Caisson ring types
Base ring — the base ring is a standard ring supplied without the tongue section of the joint so it sits flat on the cutting shoe. Base units may be fitted with a light-duty (10mm) or medium-duty (20mm) cutting shoe.
Riser rings — standard rings with fixing sockets cast into the top and bottom of the outer wall, so rings can be stacked and bolted together with purpose-designed plates, washers and bolts.
Cover and landing slabs — shaft slabs and cover slabs are available to complete the chamber for traffic or access loading.
Typical applications
- Pumping stations and wet wells
- Combined sewer overflow (CSO) and stormwater storage chambers
- Micro-tunnelling launch, drive and reception shafts
- Jacking pipe thrust pits
- Deep manholes and inspection chambers
- Attenuation and storage shafts below the water table
- Access shafts for utilities and water infrastructure
Key benefits of FP McCann caisson rings
- Faster, cleaner and more accurate shaft construction than in-situ alternatives
- Reduced excavation footprint and less time spent working in open excavations
- Bolted ring joints for maximum structural integrity
- Bespoke cutting shoes available to aid sinking in difficult ground
- Diameters DN2100 to DN4000, with DN4000 supplied as a two-piece unit
- UK manufacture to BS EN 1917 / BS 5911-3, under an ISO 9001 quality system
FP McCann caisson ring range (DN2100 – DN4000)
*DN4000 supplied as a two-piece unit.
Caisson Rings – Table of Weights (DN 2100 – 4000)
Standards and certification
Caisson rings are manufactured within the scope of FP McCann’s ISO 9001 accredited Quality Management System and in accordance with BS EN 1917 and BS 5911-3 where appropriate. Caisson manholes cannot be CE marked because their diameters fall outside the scope of the harmonised European Standard BS EN 1917; however, DN2100 to DN3000 manholes are kite-marked against the complementary British Standard BS 5911-3. DN3600 and DN4000 diameters are manufactured within the scope of the ISO 9001 accredited Quality Management System.