A Common Tower is a temporary structure that is tied to the main building and is used in conjunction with rack & pinion construction hoists to provide access into the building under construction.

A construction team working on a high rise tower will need to ensure that they have the most efficient access system available for getting personnel and materials to the work face whilst keeping the minimum opening, for access into the building. This concentration of hoisting in one area allows cladding to be installed around the open faces of the building, except the small access point to the building from the Common Tower, and then allows for the fit out of the lower floors as the main building is being constructed and grows in height.

A Construction Access Systems (CAS) Common Tower can accommodate conventional twin car single mast hoists, large single car twin mast hoists or a temporary staircase structure on any of its faces. The Common Tower is of a modular design and is capable of adaption to different sizes and shapes to suit various site conditions and to accommodate twin hoists with up to two metres wide.

The CAS Common Tower is designed for erection and dismantling either by manual handling of the components or by crane handling of large sub assemblies of one, two or three floor Common Tower modules.

Construction Access Systems Limited’s Common Tower can be used on buildings with up to 70 storeys and heights up to 300 metres.

CAS will provide project specific design calculations and drawing for each project specifying the exact bracing layouts, leg configurations, tie quantities and spacing for the Common Tower System. CAS will work with the Temporary Works Coordinator and design teams for the project and will liaise with other trades on site such as cladding providers and hoist providers.

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 CAS Common 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.