MGF TECHNICAL FILE TRENCH BOXES. Description. Product Notes.

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1 Description Simple to assemble, robust, two sided mechanical excavation support system designed to be installed by an excavator utilising the dig and push or excavate and lower in place techniques. Normally selected for installing utility pipes where ground movement is not critical, with the size of system specified dependant upon max depth requirements and size of individual pipe sections and bedding. The system is generally suitable for trench depths of up to 7.16m, widths of up to 3.92m, pipe lengths of up to 3.0m and a pipe OD of up to 2.3m. Fabricated from fully welded Grade S x60mm or 200x100mm steel box sections to form 60mm or 100mm thick panels, the system comprises trench box bases to which up to 2 No. trench box tops may be added to achieve additional depth. The panels are propped off each other by robust telescopic struts available in a variety of lengths to suit the required width. All components in the system are connected together via simple pin and clip assemblies. MGF can supply the systems with a full range of suitable lifting and extraction chains, Edgesafe edge protection panels, Laddersafe access platforms and pole ladders, Davitsafe retrieval / fall arrest systems, Endsafe end protection panels, trench road plates and confined spaces regime equipment. Manufactured and designed in accordance with BS EN : 2002 Parts 1 and 2 Trench Lining Systems and BS 5975 (2008) Code of Practice for Temporary Works Procedures and the Permissible Stress Design of Falsework. Product Notes 1. Boxes should only be used in the configurations shown by competent persons following MGF installation guidelines. 2. Boxes should not be used in very weak ground (especially very soft clays and peats) or where significant groundwater is present. 3. Boxes are not normally suitable for usage where ground movement is an issue and are therefore not recommended for use in live carriageway situations or adjacent existing buildings or structures. 4. Flying of the box above the base of the excavation is strictly prohibited. 5. Box systems are very heavy and great care must be taken in selecting a suitable excavator for handling, installing and extracting these systems. If stacking panels on site, timber packers must be used to separate the panels. 6. Boxes should not be left in-situ for extended periods within cohesive or very weak soils as earth pressures / adhesion on the panel surfaces may increase significantly with time requiring additional extraction forces to release the panels. 7. Always use MGF specified extraction chains to release an in-situ box from the ground prior to any attempt to lift the box out of the trench. Always use MGF specified lifting chains when lifting and handling the boxes or components. NB If a box becomes stuck extraction forces of up to 500kN (50t) can be required to release each corner. 8. Prior to every lifting operation all lifting points must be carefully inspected by a competent person for evidence of damage. 9. Always enter box via a ladder located within the box and never, from an unsupported edge. 10. During lifting or extraction operations ensure personnel are well clear of the equipment. 11. Ends of trench runs should always be battered back at a safe angle or end protection panels should be used. design@mgf.ltd.uk 2.1.1

2 MGF Edgesafe - See Section 6 MGF Laddersafe - See Section 6 MGF Pole Ladder MGF Endsafe Panel - See Section 6 MGF Trench Box Top MGF Trench Box Base Tel

3 Telescopic Strut Detail Telescopic strut inners and outers are connected using a pin and R-clip detail. 60 Thick Panel Connector Details Panels connect to each other using a fork connector, pin and R-clip detail. 100 Thick Panel Connector Details Panels connect to each other using a drop down connector, a pin and R-clip detail. design@mgf.ltd.uk Strut Pocket Pin Detail Telescopic struts are connected to the panel pockets using a pin and R-clip detail. Handling Point All Trench Boxes are lifted and handled by attaching MGF lifting chains to the handling points as shown

4 Product ID Description L H Alternative Name Base Mini Base LW Base Lightweight Mini Base Top Mini Top Base Standard Base Top Standard Top Base Titan Base Max Depth** (m) Panel Resistance SWL (kn/m 2 ) Panel Thick/ Weight T(mm)/(kg) Approx Assembled Weight (kg) Internal Trench Width* Wi(mm) Trench Width* We(mm) Clearance Below Bottom Struts C(mm) Clearance Between Struts Li(mm) Telescopic Strut Type N/A 5.71 N/A /586 60/435 60/ / / / N/A 1225 N/A * Greater widths (up to 5m) possible utilising Telescopic Strut Adaptors ** Max depths achievable using a base and 2 tops Tel

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6 100 Telescopic Struts Component 100 Telescopic Struts Strut Inner Strut Outer Specification 100x100x10 SHS 120x120x8 SHS Material Grade S355 S355 Axial SWL 228kN 228kN Moment SWL 9.9kNm 9.9 knm Hole Details Φ30mm holes Φ30mm holes Unit Mass 27.4kg/m 26.4kg/m 150 Telescopic Struts Component 150 Telescopic Struts Strut Inner Strut Outer Specification 150x150x12.5 SHS 180x180x10 SHS Material Grade S355 S355 Axial SWL 492kN 492kN Moment SWL 38.9kNm 38.9kNm Hole Details Φ48mm holes Φ48mm holes Unit Mass 52.7kg/m 50.7kg/m Tel

7 Telescopic Strut Pins and Retaining Clips Component 100 Strut Pin 150 Strut Pin Specification Ø28mm round bar, 160mm long Ø45mm round bar, 220mm long Material Grade 080M40 (EN8) 080M40 (EN8) Shear SWL 228kN 492kN Weight 1kg 3kg Trench Box Connector Pins and Retaining Clips Component 60 Thick Panels 100 Thick Panels Specification Ø40mm round bar, 100mm long Ø32mm round bar, 210mm long Material Grade 080M40 (EN8) 080M40 (EN8) Shear SWL 384kN 308kN Weight 1kg 1kg 2.1.7

8 100 Telescopic Strut Combinations Range (mm) Inner Type Outer Type Strut Weight (kg) Telescopic Strut Adaptors 200 x 200 SHS - Trench Box Strut Adaptor (500mm long) This adaptor will allow MGF 200 Series struts to be used as Trench Box struts. Range (mm) Product ID Weight (kg) 27 Section Material Grade 100x100x10 SHS S Tel

9 150 Telescopic Strut Combinations Range (mm) Inner Type Outer Type Strut Weight (kg) Telescopic Strut Adaptors 200 x 200 SHS - Titan Trench Box Strut Adaptor (500mm and 600mm long) This adaptor will allow MGF 200 Series struts to be used as Titan Trench Box struts. Range (mm) Product ID (500mm) (600mm) Weight (kg) 40 (500mm) 45 (600mm) Section 150x150x12.5 SHS Material Grade S355 design@mgf.ltd.uk 2.1.9

10 Maximum Recommended Depths / Configurations Tel

11 Typical application showing a Manhole Box connected to a run of Trench Boxes. design@mgf.ltd.uk

12 MGF Manhole Box Tel