The Common Tower is used in conjunction with rack and pinion construction hoists to provide access from the hoist cars into the building under construction, and to provide a means of transmitting the tie forces from multiple hoists to common tie points on the building structure.

The Tower is based on a five metre square arrangement to accommodate conventional twin car single mast hoists or large twin mast single car hoists on any of its faces. The Tower design is modular and capable of adaption to different sizes and shapes to suit various site conditions and to accommodate twin hoists with cars up to two metres wide. The Tower is designed for erection and dismantling either by manual handling of all components or by crane handling of large sub assemblies. The Common Tower can be used on buildings with up to 70 storeys and heights up to 300 metres.

The Tower is designed as a temporary structure using the principles of BS5975:2008 “Code of Practice for Temporary Works Procedures and the Permissible Stress Design of Falsework”. To achieve the low component weights required for manual handling extensive use is to be made of aluminium components and these are designed in accordance with BS 8118:Part 1:1991 “Structural Use of Aluminium”.

Project specific design calculations and drawings will be prepared for every use of the Common Tower System specifying the exact bracing layouts, leg configurations, tie quantities and spacing.

Component Testing

To back up design calculations CAS has been working with the University of Southampton Research Institute for Industry. A number of tests were performed to determine the buckling load of the leg stanchions of the Common Tower System.

The tests were conducted using the University’s column testing machine in the Heavy Structures Laboratory.

Common Tower Long Leg Stanchion Test
Long Leg Stanchion Test

Common Tower Short Leg Stanchion Test
Short Leg Stanchion Test

Common Tower System Testing