Roof Suspensions - Altrex MHB 60 Manuel

8. Roof suspensions

- Altrex roof beams:
- ADB 600 LOW (WLL 600 kg)
- ADB 600 HIGH (WLL 600 kg)
- ADB 800 LOW (WLL 800 kg)
- ADB 800 HIGH (WLL 800 kg)
- Roof beams are designed and classified for a certain Work Load Limit
EN
(WLL). The WLL specifies the maximum capacity for the hoist used.
- Altrex roof beams can only be used on flat roofs.
- Before assembling the installation, check the load bearing capacity of
the roof construction of the building to work on. During normal operation, the roof beam's front support stand carries a
maximum load of 1150kg and the rear supports a maximum of 700kg.
- To support the load by the roof, it might be necessary to use suitable underlayment for load distribution.
- Under extreme conditions these values are higher; the load on the front support stand can be up to 3000kg
- Note that the roof must be able to resist the load generated in an extreme case (as with a cable break)!
8.1 Preparation
Study the configuration and load tables in appendices T5 and T6
- Determine the type of roof beam that is going to be installed
- Determine the length of required 'outreach B'
- ADB 600 LOW / ADB 600 HIGH
- ADB 800 LOW / ADB 800 HIGH: 0,9m or 1,2m
- Determine the distance between the front- and rear trestle: 'supportdistance
A' that is required: 4,5m / 5,0m / 5,5m.
- See annex T9. Find the hoist capacity (WLL) of the hoist that will be applied.
On the junction of support distance A and hoist capacity, the required number
of counterweights (20 kg) is found.
- Example: a roof beam 400-600 HIGH is installed, with an outreach
B of 1,2m and a support distance A of 5,0m. The applied hoist
has a WLL of 600kg. From the load capacity table (annex 9) it can be
seen that 20 weights of 20 kg are required.
- Determine the required length of the steel and electrical cables. Only use cables that comply with the hoist
manufacturer specifications. For the steel cables, include a minimum of 10 metres in addition to the height of the
building.
8.2 Safe working on roofs
- If the roof on which a roof suspension is to be assembled offers safety by means of a parapet or a permanent guardrail
of at least 1m in height, no fall arrest equipment has to be used.
- If work has to be done within 4m from the edge of a roof that offers no safety by means of a parapet or guardrail of
sufficient height, the following applies:
- No work may be carried out unless a roof offers a suitable point for anchorage of personal fall-arrest equipment,
which is compulsory. This applies while assembling, relocating or disassembling the roof suspension structure.
- If the roof has a parapet of at least 10cm in height, a completely built up roof beam with counterweight and with
wheels in braked position may be used as point of anchorage for fall-arrest equipment. The shock absorber arm
should be used to connect the fall-arrest equipment to the roofbeam. This applies only for roofbeams which are
completely installed, including all required counterweights.
- In all other cases a different way of fall-protection has to be arranged, e.g. by edge protection or a mobile point
of anchorage.
- Roof beams may only be assembled, relocated or disassembled in good weather conditions and a maximum wind force
of 6 Beaufort.
- Roof beams may not be assembled, relocated or disassembled in storm, snow, hail or icy conditions.
8.3 Roof beam assembly/mounting
Study the configuration and load tables in appendices T8 and T9. Check that all components are present.
Caution: the front trestle and the rear trestle must always be at the same height (an equal horizontal plane).
8.3.1 ADB 600 (LOW and HIGH)
1. Assemble the outer beam, with the inner beam inserted in the outerbeam, to the desired length ('support distance A:
4,5m, 5,0m of 5,5m). Secure the beams with locking pins and lock them using the red quick-pin.
2. Slide the outer beam into the front trestle, until the 1st locking hole on the beam is aligned with the locking hole on the
front trestle (This is the 2nd locking hole if using extended outer beam 415095)
3. Slide the front beam into the outerbeam until the desired outreach (Outreach B). Secure the front beam, front trestle
and outer beam with the locking pin. Secure the locking pin with the red quick-pin.
4. Slide the outer beam into the rear trestle, until the 1st locking hole on the beam is aligned with the locking hole on the
rear trestle.
5. Slide the shock-absorber adaptor into the outer beam. Secure the shock-absorber adaptor, rear trestle and outer beam
with a locking pin. Secure the locking pin with the red quick-pin.
18 www.altrex.com
- standard: 0,9m or 1,2m
- with extended front beam (415095): 1,6m / 1,9m / 2,2m