Construction equipment tends to play a number of roles in keeping a site running smoothly. Take the trench box, for example.
Trench boxes are one of the most commonly used pieces of safety equipment in construction. They have several uses on a construction site, used during excavations, and for the installation of sewer pipes and underground cabling.
In excavations, trench boxes are used to prevent the excavated wall faces from collapsing, keeping workers safe from injury or death. Not only do trench boxes help keep construction projects safer, they also help them run more efficiently, with a range of time-saving benefits.
This guide covers everything you need to know about trench boxes. From what they do, how they work, and how they are used on construction sites.
Trench boxes work by shoring the edges of excavations to prevent the ground from caving in, protecting workers from full collapses or dislodged materials.
They use simple two-sided systems to hold each face of the excavation in place. Each side has its own trench shield, held by adjustable beams to brace the excavation walls and prevent collapse.
This makes excavation environments safer to work in, and their simple assembly allows for quicker construction. Trench boxes can also protect workers from falling into excavations, with the addition of edge protection barriers and other safety equipment.
Safety is the number one reason to use shoring equipment such as a trench box in excavations. Put simply, if you excavate a hole in the ground, the ground all around it becomes unstable and could collapse.
Did you know that, depending on the type of ground, a cubic metre of soil can weigh more than 1.5 tonnes? That’s the equivalent of a mini excavator.
That kind of load falling on construction workers can easily result in the injury and loss of life of those within the excavation. According to the Health and Safety Executive (HSE), there were 38 deaths in the construction industry in 2017-18, and 12 per cent of those were as a result of people being trapped by something collapsing.
Are trench boxes a legal requirement?
The HSE states in Regulation 22 of the CDM Regulations that “all practicable steps must be taken to prevent danger to any person, and to ensure that no excavation or part of an excavation collapses”.
For certain types of excavation, a correctly installed trench box is vital to guarantee workers’ safety.
Do trench boxes require edge protection?
Edge protection is required alongside trench boxes for excavations exceeding 5 feet deep. In some cases, edge protection is required for excavations less than 5 feet deep if the soil is not stable enough.
Edge protection systems are highly recommended for use with trench boxes. Protective barriers can help prevent workers from falling into the excavation, as well as protect workers in the excavation area from dislodged materials.
By making sure your trench is safe, you could also be saving yourself time. Some sites may batter or bench an excavation (which means creating ‘steps’ out of the soil at the side or excavating the ground out on a gentle slope at each side so that the loose material isn’t vertically piled up).
However, using a trench box is usually more effective than battering or benching. Without a trench box, the ground may still collapse if there’s nothing holding it back - posing a real safety issue.
Additionally, a collapsed trench will have to be excavated out again. That means loss of time – something in short supply on a construction site.
With a trench box, the amount of material that needs to be removed is substantially less than a battered or benched excavation – so it’s quicker. It also means safe excavations can be carried out in constrained site environments with a trench box.
If you have a manhole to take into account, our manhole box range has been designed in conjunction with our trench box systems to allow for rapid installation of manhole construction.
There are many benefits to using temporary works equipment on site. Trench boxes are lightweight and easy to install, made using minimal components to help workers assemble the trench box without disruption to the project.
Plus, trench boxes can be used in combination with many other types of safety and support equipment in order to make construction more efficient.
For example, Drag Boxes can be used in cohesive ground to allow quick installation of pipes and other underground services. Or, Rolling Strut Boxes, which have panels that can move vertically independently from each other and have a maximum internal width of 6.7 metres and can be used as an alternative to trench sheets and hydraulic frames.
Our job is to help our customers deliver their projects more quickly, safely and efficiently, and all of those aspects have been taken into account when we designed our box range.
We can cater for lots of different requirements. If you need help in finding the right trench box, the dedicated section of our website or technical hub can help. Alternatively, you can contact your local depot or contact us online.
Trench Boxes are used for rapid shoring of trench runs. These, together with Drag Boxes and Manhole Boxes, provide a quick and easy way of holding the ground stable in a trench without the need to use any other shoring equipment.Find out more