Weisman Consultants - Engineering of Self-Supporting Towers and Guyed Masts

Weisman Consultants Inc. has been supplying structural engineering consultancy services to the communication and wireless industry for the past 22 years. We specialize in unusual cases, to which we bring our varied experience and creative talents, to solve problems in new ways that provide the best results for our clients with the minimum possible cost and risk to them.

We have performed designs for towers used in broadcasting, telephony, wireless cellular, radar, shortwave radio, and supports for wind turbines. These designs included triangular and square lattice towers (both self-supporting and guyed), tubular (both cylindrical and tapered, with round and polygonal cross-sections), and systems mounted on other structures such as rooftop and wall installations.

Our work covers all structural engineering aspects of tower design including: design, design drawings, fabrication drawings, installation drawings, bills-of-material, inspection, and project management. We also perform third party design reviews, analyses and investigation of failures.

GUYED MASTS

We have designed guyed masts of up to 450m and reviewed designs by others of masts of up to 600m. We have also designed upgrades for guyed masts using various means including the addition of new verticals to shunt load off the old verticals, the addition of new mast sections linked rigidly to the old mast sections to considerably enhance the capacity of the mast system, the change of guying configurations to improve the mast's performance with a minimum of disruption to services.

A guyed mast is very sensitive to even small changes in the distribution of loads and small changes in guy stiffness. Maximizing the performance of these structures requires a good understanding of their behaviour and response to subtle changes in the various parameters of design. Having spent many years working with guyed masts, we are well acquainted with their behaviour. We also have software to help us model guyed masts with considerable fidelity, giving us great confidence in our results and a preparedness to provide excellent support to our clients in cases of dispute.

SELF-SUPPORTING TOWERS

Self-supporting towers are in many ways simpler than guyed towers, but still present a great potential for imaginative engineering work. We have designed self-supporting towers of both square and triangular cross-section, tapered and prismatic, built of elements made of structural shapes (angles, wide flange, channel, pipe) or built-up sections normally used for building guyed masts.

TOWERS FOR WIND TURBINES

The heaviest square self-supporting tower designed by us was a 50m lattice tower to support a 300kW wind turbine, of which seven were built in India. In a tower for a wind turbine, there are restrictions on face width and geometry as well as on its natural frequency of vibration. The lightest was a 25m triangular tower to support an 85kW turbine. This tower was hinged at the base to facilitate its assembly on the ground and tilt-up using a tractor or truck, so that no crane was required for installation. This approach is appropriate for remote regions.

UPGRADING TOWERS AND MASTS

Our upgrades of existing towers is of particular advantage to our clients. We think outside the box to come up with innovative, economical solutions. In many cases an old tower or mast can be made to serve more carriers better through upgrading.

SOFTWARE

We produce, distribute, and support the use of the GUYMAST family of computer software for the analysis and design of communication and broadcast towers and masts.

Our software includes programs to calculate wind, gravity, and ice loads imposed on the tower, programs to analyse the structure and return numerical and graphical data showing deformations, member forces, and loads onto the foundation.

DRAWMAST produces a profile drawing of the tower or mast based on the data used in the analysis. This drawing is suitable for checking the model and, also, for inclusion in a submittal of an analysis report or bid document for supply of the tower by a contractor.

SITE SPECIFIC DESIGN WIND AND ICE

Weisman Consultants Inc. can provide, through a sister company, proper estimates of design wind speeds and ice thickness. We have access to meteorologists who can provide these values based on statistical data and our evaluation of the effects of local topography.