In the previous part we examined innovations of the conventional davit systems. It is worth recapping that the increasing frequency of davit installations is because this avoids many considerations associated with more traditional anchor points such as abseil posts or eyebolts. British Standards necessitate that height safety equipment and building substructures such as parapets or balustrades can meet the design loads associated with these products. These are at least 2.5 times greater than the service load of 6kN.
The design loads are specified to ensure that in the event of an accidental fall, there is no risk of debris falling. If this did occur it could cause an injury or fatality to the operative or a member of the public. Effectively, socketed davits were the first solution to an emerging rope access requirement for new buildings.
All the way through to the early 2020’s these sockets were most frequently chemical anchor fixed however since this time it has become more and more prevalent for these to be ‘cast-in’ during a concrete pour to significantly reduce the complexity and cost associated with ongoing 6 monthly LOLER examinations.
Despite this development, the main down side to socketed davit solutions still exists. The lifetime cleaning costs with this system are so much greater than other BS8610 / EN17235 anchor solution options. The increase in time and cost is predominately a factor of set up and rigging times. During Sayfa Group’s product development consultation with IRATA rope access technicians, it became evident that whilst Davits work for the building design, they do not work for the user and therefore not the building owner / duty holder.
The feedback to us was that Abseil rail was the much preferred but not if accessibility of these was made difficult by being outboard of the building or overhead. The issue with a conventional abseil rail in other scenarios is that rope loadings will still be applied to the parapet or balustrades.
On this basis Sayfa Group has developed a range of hybrid rail and davit products. These deliver a safer, more intuitive system that allows horizontal access across the facade, minimising rigging and set up times but also deviating the rope path. Whilst the initial costs of these new systems can be the same or even slightly more than a socketed davits, the life cycle cost saving can be £100,000's.
On larger schemes life time cost saving have been calculated to be in excess £1.5 million. Additionally, interruptions to the building from aspects such as exclusion zones or access closures are limited.
In summary life costs are a factor of:-
Height / Facade Access Strategies
Building superstructure cost
Possible facade re-enforcement cost
System Designer cost
Initial product system cost
System and commissioning
Ongoing LOLER examinations
User / Cleaning or Maintenance costs
Providing 3 or 6 monthly cleaning and certification cycles are maintained, all other costs can be best represented by the iceberg analogy, the design and build costs are the little that is visible above the water - the maintenance and use are the vast amount unseen below the water.
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