Marshalls CPM offer a range of reinforced precast concrete manhole units specially designed for sinking by the caisson method from 2000mm diameter to 4000mm internal diameter in varying depths (please see table below).

This is achieved by using a shaft sinking plate system and is made in accordance to BS EN 1917:2002 and kitemarked where relevant to BS 5911-3:2010.

Advantages of the systems include:
  • Suited to weak soils, high-plasticility clays, silts, sands and gravel
  • Minimal site labour costs
  • Quick and easy to install
  • Fast, clean accurate construction
  • Immediate permanent shafts
  • Suitable for jacking pits

The caisson shaft sinking system was originally designed for use in microtunnelling, but is now more widely used for construction of pumping stations, wet wells and manholes, particularly in difficult ground conditions.

Caisson chamber section weights and dimensions
Click image to enlarge
Caisson chamber section weights and dimensions notes:
  1. 4000mm chambers are supplied in two half sections, each weighing approximately 3180 kg per metre, for assembly on site.
  2. The steel cutting shoes are fitted to the base section providing a 10mm overbreak on all except 3660mm and 4000mm which provide a 20mm overbreak.
  3. Cutting shoes with a larger overbreak can be manufactured upon request.
  4. + Non-kitemarked
  5. Caisson lifting equipment is available for purchase from Marshalls CPM on 01179 814500 or
Caisson cover slab weights and dimensions
Click image to enlarge

Weights are based upon 675 x 675 opening or similar

Reference is strongly recommended to the Caisson Installation Guide

For sales into England and Wales please call 01179 814500 or email

For sales into Scotland please call 01698 386922 or email


Click on the images below to view the image gallery.

Got a question?

To find out more about Caissons, please call our Sales Team or fill out the enquiry form and we’ll get back to you within 24 hours.

Let us help find what you need

Select from our list below to explore our solutions in detail

Search by application

Select from our list below to explore our applications in detail