Lightweight Manhole Box Systems

A lightweight, four-sided trench shield system for safe manhole and chamber installations

End return panels for 360-degree support
Up to 34.1 kN/m² permissible earth pressure
Compatible with standard mid-sized excavators
940mm vertical pipe clearance
Available for sale and hire
Nationwide delivery or depot collection

Site Equipment Limited's Lightweight Manhole Box system provides secure, four-sided trench support for installing concrete manholes, pumping stations, and interceptor chambers. Designed with integrated end return panels, it offers complete perimeter protection while remaining light enough to be handled by smaller excavators than our heavy-duty Standard system.

Available for sale and hire across the UK, this modular system pairs 2.00m base boxes with 1.00m top boxes. It is the ideal solution for urban sites and restricted groundworks where heavy lifting capacity is limited but continuous perimeter ground support is strictly required.

Core capabilities and applications

Ideal for manholes and chambers. If you are excavating for a precast concrete manhole ring or a small chamber, a standard trench box is often insufficient because it leaves the ends of the excavation exposed. The Lightweight Manhole Box solves this by providing enclosed support, making it ideal for:

Installing precast concrete manhole rings
Constructing small pumping stations and interceptor chambers
Square or rectangular excavations requiring four-sided support
Urban or restricted sites with limited plant access

For deeper or exceptionally large chamber excavations, we recommend upgrading to our Standard Manhole Box System, which offers greater permissible earth pressure and depth capacities.

Operational mechanics and installation

Four-sided protection. Unlike standard trench boxes, the Lightweight Manhole Box incorporates built-in end return panels. These secure the open ends of the excavation, ensuring groundworkers are fully protected from all sides while working within the chamber footprint.

Dig and push deployment. The system is installed using the standard "dig and push" technique. The base box is placed in a shallow pre-excavated trench (subject to ground conditions), and an excavator digs from within the box, pushing the heavy steel panels down incrementally as the excavation progresses. This ensures the trench walls are never left unsupported.

Modular depths and widths. Available in lengths from 2.00m to 4.00m, the system uses a 2.00m-high base box that can be extended with 1.00m-high top boxes. The internal working width can be adjusted from 1.33m up to 3.88m using interchangeable spindles (Types A to F).

Temporary Works Design

Achieving safe manhole installations requires rigorous engineering oversight. Here at Site Equipment Limited, we provide full Temporary Works Design services from our in-house engineering team to ensure our Lightweight Manhole Box system is specified correctly for your exact ground conditions and depth requirements.

Lightweight Manhole Box: Common Questions

When should I use a manhole box instead of a trench box?

You should use a manhole box instead of a trench box when you are installing a concrete manhole or chamber and require four-sided perimeter support. Manhole boxes feature integrated end return panels to secure the ends of the excavation, whereas standard trench boxes only support two sides.

What sizes do the Lightweight Manhole Boxes come in?

Our Lightweight Manhole Boxes come in plate lengths ranging from 2.00m to 4.00m. The system utilises a 2.00m-high base box, which can be extended using 1.00m-high top boxes to reach the required depth.

What is the difference between the Lightweight and Standard Manhole Box?

The primary difference is that the Lightweight Manhole Box is lighter and easier to handle with smaller excavators, but it has a lower permissible earth pressure capacity compared to the heavy-duty Standard Manhole Box.

What is the maximum pipe clearance height for the Lightweight Manhole Box?

The maximum vertical pipe clearance height for all 2.00m high base boxes in the Lightweight Manhole Box system is 940mm.

How much does it cost to hire a Lightweight Manhole Box from SEL?

The cost to hire our Lightweight Manhole Box depends on the box length, the number of top boxes required, and the duration of your project. Please contact our hire desk for a competitive, job-specific quotation.

Sale and Hire of Lightweight Manhole Box Systems

We supply Lightweight Manhole Box systems for sale and hire across the UK, backed by expert technical advice. Please contact SEL for further information or to get a competitive quote from your nearest depot.

Lightweight Manhole Box Summary

Plate Length L	Plate Height H	Pipe Clearance Length LC	Permissible Earth Pressure
m	m	m	kN/m²
2.00	2.00 base 1.00 top	1.60	34.1
2.50	2.00 base 1.00 top	2.10	30.0
3.00	2.00 base 1.00 top	2.60	25.0
3.50	2.00 base 1.00 top	3.10	18.9
4.00	2.00 base 1.00 top	3.60	23.0

All 2.0m high base boxes have a vertical pipe clearance height (Hc) of 940mm

Lightweight Manhole Box Weights

Box Length	Panel Height	Weight per box Please refer to the spindle chart below.
m	m	kg
m	m	Type A	Type B	Type C	Type D	Type E	Type F
2.00 C	2.00 Base 1.00 Top	1063 634	1074 640	1090 648	1100 653	1109 658	1123 665
2.50 D	2.00 Base 1.00 Top	1181 690	1192 696	1208 704	1218 709	1227 714	1241 721
3.00 E	2.00 Base 1.00 Top	1303 746	1314 752	1330 760	1340 765	1349 770	1363 777
3.50 F	2.00 Base 1.00 Top	1649 810	1660 816	1676 824	1686 829	1695 834	1709 841
4.00 F	2.00 Base 1.00 Top	1897 1038	1908 1078	1924 1086	1934 1091	1943 1096	1957 1103

The letter indicates the recommended spindle size where a square excavation is required

A forklift/machine must be provided to off load the kit from the delivery vehicle. Alternatively SEL can deliver the equipment on a HIAB vehicle by prior arrangement.

Spindle Chart

Spindle type	Working width bC		Excavation width b		Permissible axial force	Weight
	m		m		kN	kg
	min.	max.	min.	max.	kN	kg
A	1.33	1.53	1.46	1.66	160	14.2
B	1.51	1.87	1.64	2.00	147	16.9
C	1.85	2.45	1.98	2.58	124	20.9
D	2.30	2.90	2.43	3.03	107	23.6
E	2.68	3.28	2.81	3.41	92	25.8
F	3.28	3.88	3.41	4.01	69	29.3

The width of excavation increases by 40mm when 4.0m boxes are employed.

Lightweight Manhole Box User Guide

Lightweight Manhole Box Information Sheet

Essential handling accessories and alternative systems

We can help with your next project.

Our team is friendly, knowledgeable and ready to consult. We offer no-obligation site visits, fast delivery and competitive rates. Simply fill in the form and we'll be in touch.

You can also give us a call at any time.