1. Lay Trench Box panel down on a level surface on suitable timber bearers using the 4-Leg chain provided.
Secure the lifting hooks through the handling points at the upper and lower ends of the channels.
2. Spin out Spindles to the required length and position into the channels alternating as shown. Ensure that the lower Spindles are extended by 30-50mm more than the top spindles.
Secure using Pins & R-Clips as shown in Detail A.
3. Lower opposite panel onto spindles using the 4-Leg chain.
Chain hooks to be secured to the handling points at the upper and lower ends of each channel.
Secure to spindles using Pins & R-Clips. Do not remove slack in the chains until all the spindles are secured.
4. Lift box into upright position using the 4-Leg chain secured through the upper handling points.
For narrow trench boxes, it is recommended to temporarily place the box into a shallow flat bottomed trench for stability.
5. Where required, lower Top Box onto Base Box (assembled as Stages 1-4). A second spindle could be used for ease of installation.
Secure to Base box using Pins & R-Clips as shown in Detail A.
6. Lift box into preformed trench excavated in stable ground. A competent person should assess the ground conditions, ensuring that the ground is temporarily stable and self-supporting.
A minimum 50mm upstand is recommended.
7. Install suitable edge protection and access where required. Ensure that the open end of the excavation is battered to a safe angle as determined by the Contractor or closed with suitable end closure.
The removal of the boxes should be performed sequentially. Once the permanent works are installed, the contractor should backfill inside the box in layers not exceeding 500mm.
Once the backfill is compacted to the Permanent Works design standard, the box can be lifted by a maximum of 500mm.
Using a single chain leg, pull each corner of the box slightly before attempting to lift the whole box using the 4-Leg chain.
Repeat this process until the boxes can be removed completely.