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sealed manholes

Sealed Manholes

After an extensive research programme, Marshalls Civils and Drainage introduced the 1200mm Sealed Manhole system in October 2009 to meet the challenges of modern day construction. Today, it is available in 1200mm, 1500mm and 1800mm diameters and comprises of a monolithic precast concrete base (available pre-benched in any configuration, a sealed chamber ring (with a thicker wall than a standard ring), a rubber joint (so no tokstrip of similar product is required) and a sealed cover slab which is supplied with your required access.

This unique system of products combines to form the Marshalls Civils and Drainage Sealed Manhole system; designed and manufactured to last a minimum of 120 years that provides a sealed manhole system that gives up to 40% savings on greenhouse gases compared to traditional manhole construction and eliminates the need of ready mixed concrete to form the traditional base, chamber benching and further concrete to surround the manhole. A complete manhole can be installed in as little as 30 minutes, making safe site practice a real winner when using the Perfect Manhole as it reduces the need to work in confined spaces and eliminates the need for wet trades resulting in rapid construction compared to traditional methods as well as a reduction in the time the excavation is open.

The Sealed Manhole complies with BSEN 1917:2002 and BS5911-3 and has been accepted for use by all major UK companies.

Advantages of the Sealed Manhole System:

  • Safer construction – No requirement to work in confined spaces. No requirement to form a concrete surround. Reduction of open excavation.

  • GHG Savings – Up to 40% savings on GHG emissions compared with traditional build.

  • Fast installation – The modular solution eliminates the need for wet trades resulting in rapid construction compared to conventional methods.

  • No need to surround in concrete unless specifically required – 130mm wall thickness.

  • Available at short notice – Our modern methods of production enables just in time delivery of all components including monolithic bases at short notice.

  • Design freedom – All designed monolithic perfect base characteristics such as location of the inlets and outlets and invert configuration can be manufactured individually and exactly in accordance to the wishes of the specifier and client.

  • Perfect Hydraulics – everything flows. Optimised flow characteristics by customised base configuration of all inlets and precise drop in channels and pipe connections.

  • Watertight – The combination of a thicker wall and rubber joints ensures a watertight structure.

  • No water ingress into sewerage network reduces treatment costs – The combination of a 130mm wall and sealed rubber joint to withstand a minimum of 5m / head pressure*

  • Combined seal includes load distributor – Load distribution ensures even distribution of vertical loads*.
  • Allows joint inspection – Correct installation can be visually confirmed.
  • Efficient construction – Available in varying depths for efficient construction.
  • Base options – available pre-benched or plain bottom with or without inlet/outlets.
  • Pre-fit options – Hydro-brakes, penstocks, non-return valves and filters can be pre-fitted at the factory.
  • Flexible connections – The perfect manhole can connect to plastic, clay or concrete giving you a larger choice.
  • Fully tested under factory conditions – The whole system from base to cover slab is subject to testing.
  • Kitemarked solution manufactured under factory conditions – Complies with the requirements of BSEN 1917 and BS5911-3.
  • Concrete for Life – Built to last. High quality durable concrete with a minimum 120 year design life.
  • Full take-off service available.
  • Lifting apparatus available for fast, effective and safe handling.
  • *Please note Watertightness is defined in BS EN 1917 as resisting a 5m head for 15 minutes, this is to simulate a temporary surcharge condition not a permanent head of water. Shafts in high water tables are subject to buoyancy effects.

    We have some useful video's on the perfect Sealed Manhole System and also on how to install the best system.

    If you would like a CPD style presentation on the Sealed Manhole please call our marketing team on 01902 356220 or email lch@marshalls.co.uk

Product Name Overall Diameter (mm) Product Height Min (mm) Product Height Max (mm) Height Including Spigot Min (mm) Height Including Spigot Max (mm) Depth To Double Step (mm) Depth To Invert Max (mm) Fill Height (mm) Wall Thickness (mm) Weight (kg)
DN1200 x 100mm Diameter Outlet 1460 400 600 475 675 155 525 150 130 1550
DN1200 x 150mm Diameter Outlet 1460 450 650 525 725 155 575 150 130 1700
DN1200 x 225mm Diameter Outlet 1460 525 725 600 800 155 650 150 130 1900
DN1200 x 300mm Diameter Outlet 1460 600 800 675 875 155 725 150 130 2100

*Overall Diameter 'A' , Product Height 'B', Height Including Spigot 'C', Depth To Double Step 'D', Depth To Invert 'E', Fill Height 'F', Wall Thickness 'T', Weight 'Max'

Product Name Overall Diameter (mm) Product Height Min (mm) Product Height Max (mm) Height Including Spigot Min (mm) Height Including Spigot Max (mm) Depth To Double Step (mm) Depth To Invert Max (mm) Fill Height (mm) Wall Thickness (mm) Weight (kg)
DN1500 x 525mm Diameter Outlet 1960 965 1165 1050 1250 155 1050 200 230 5550
DN1500 x 600mm Diameter Outlet 1960 1040 1240 1125 1325 155 1125 200 230 5850
DN1500 x 675mm Diameter Outlet 1960 1115 1315 1200 1400 155 1200 200 230 5950

*Overall Diameter 'A' , Product Height 'B', Height Including Spigot 'C', Depth To Double Step 'D', Depth To Invert 'E', Fill Height 'F', Wall Thickness 'T', Weight 'Max'

Product Name Overall Diameter (mm) Product Height Min (mm) Product Height Max (mm) Height Including Spigot Min (mm) Height Including Spigot Max (mm) Depth To Double Step (mm) Depth To Invert Max (mm) Fill Height (mm) Wall Thickness (mm)
DN1800 x 100mm Diameter Outlet 2440 675 875 760 960 155 685 275 320
DN1800 x 150mm Diameter Outlet 2440 725 925 810 1010 155 735 275 320
DN1800 x 225mm Diameter Outlet 2440 800 1000 885 1085 155 810 275 320
DN1800 x 300mm Diameter Outlet 2440 875 1075 960 1160 155 885 275 320
DN1800 x 375mm Diameter Outlet 2440 950 1150 1035 1235 155 960 275 320
DN1800 x 400mm Diameter Outlet 2440 975 1175 1060 1260 155 985 275 320
DN1800 x 450mm Diameter Outlet 2440 1025 1225 1110 1310 155 1035 275 320
DN1800 x 525mm Diameter Outlet 2440 1100 1300 1185 1385 155 1110 275 320
DN1800 x 600mm Diameter Outlet 2440 1175 1375 1260 1460 155 1185 275 320
DN1800 x 675mm Diameter Outlet 2440 1250 1450 1335 1535 155 1260 275 320
DN1800 x 750mm Diameter Outlet 2440 1325 1525 1410 1610 155 1335 275 320
DN1800 x 825mm Diameter Outlet 2440 1400 1600 1485 1685 155 1410 275 320
DN1800 x 900mm Diameter Outlet 2440 1475 1675 1560 1760 155 1485 275 320

*Overall Diameter 'A' , Product Height 'B', Height Including Spigot 'C', Depth To Double Step 'D', Depth To Invert 'E', Fill Height 'F', Wall Thickness 'T', Weight 'Max'

Product Name Weight (kg)
DN1200 - 600x600 Access - Sealed Manhole Cover 615
DN1200 - 675x675 Access - Sealed Manhole Cover 600
DN1200 - 750x600 Access - Sealed Manhole Cover 600
DN1200 - 1200x675 Access - Sealed Manhole Cover 470
DN1500 - 600x600 Access - Sealed Manhole Cover 1170
DN1500 - 675x675 Access - Sealed Manhole Cover 1120
DN1500 - 750x600 Access - Sealed Manhole Cover 1120
DN1500 - 1200x675 Access - Sealed Manhole Cover 960
DN1800 - 600x600 Access - Sealed Manhole Cover 1630
DN1800 - 675x675 Access - Sealed Manhole Cover 1590
DN1800 - 750x600 Access - Sealed Manhole Cover 1590
DN1800 - 1200x675 Access - Sealed Manhole Cover 1440

*Overall Diameter 'A' , Product Height 'B', Height Including Spigot 'C', Depth To Double Step 'D', Depth To Invert 'E', Fill Height 'F', Wall Thickness 'T', Weight 'Max'

Product Name Weight (kg)
DN1500 x 1000mm Sealed Manhole Ring 1730
DN1500 x 750mm Sealed Manhole Ring 1330
DN1500 x 500mm Sealed Manhole Ring 860
DN1800 x 1000mm Sealed Manhole Ring 2060
DN1800 x 750mm Sealed Manhole Ring 1545
DN1800 x 500mm Sealed Manhole Ring 1030

*Overall Diameter 'A' , Product Height 'B', Height Including Spigot 'C', Depth To Double Step 'D', Depth To Invert 'E', Fill Height 'F', Wall Thickness 'T', Weight 'Max'