Full Design Duties

Requirement

Replacement

Our client had a duplex pair of ‘rack and pinion’ passenger lifts and required options to replace them with a duplex pair of more conventional traction lifts.

There were many factors to be taken into account, such as: 

• any structural alterations, 
• waiting times and usage, 
• the environment, 
• the Equality Act 2010, 
• time lines for undertaking specification, 
• tender period, 
• procurement, 
• installation and commission, 
• cost and ongoing maintenance, 
• the available space and the availability of spares should the lift breakdown, versus lift outage time.

Solution

Retention

The existing Alimak rucksack type lifts utilised a central supported mast. If this mast was removed to accommodate the new lifts, a large amount of supporting steelwork would have to be installed and both lifts would need to be dismantled at the same time, leading to additional costs and long periods with no lift service.

We suggested the central mast was retained, which would allow one lift to be replaced whilst the other lift remains in service. There would be some additional steel work required at the top of the lift shaft and, although the proposed new lift car would be larger than the existing lifts, they would be slightly smaller than they would have been with the removal of the central mast. The new guide brackets would be affixed to the central mast. 

Avoid damp issues

The lifts are in a semi exposed position, whereby it is likely that damp will enter the lift well and the lower parts of the lift are within the flood plain position. Due to the likely damp, we recommended all shaft switches and termination were IP54 rated. We also recommended a wall mounted controller to be positioned above the possible flood plain, and for the new machinery to be at the top of the shaft. Therefore, there would be minimal, or no, electrical equipment in low positions. 

Cater for high usage

From the information received, and from the evidence during our survey, the lifts can be in very high usage – particularly during the summer season. We, therefore, suggested a heavy-duty door operator and landing equipment.

Benefits

Larger better faster stronger!

The new lifts are larger, with an increased loading capacity from 21 to 24 persons as a result. They are also 1m/s faster, from 0.6m/s to 1.6m/s. In addition, they have a significantly increased handling capacity.

Energy efficient

The new lifts have a much greater energy efficiency of, what we estimate to be, between 50% and 70%. They are now weatherproof and run much quieter and smoother than the existing lifts.

Reduced expenditure

Lastly, the maintenance costs for the new lifts would be considerably reduced.