This story has been updated for the July/August 2016 Top Webex issue.

Steel behemoths stand tall, a fabricating feat

When artist Andy Scott was first appointed to create public art that makes a statement, he focused on Scotland’s industrial heritage by dreaming up two Clydesdale horses—similar to those used to help build the Scottish Canals. Roughly 35,000 motorists on a daily basis now have a reason to slow down while cruising down the A9 motorway.

Scott usually creates his artwork in his Glasgow-based studio, but the sheer size of the project required all hands on deck. Atkins, a design, engineering and project management consultancy, came in to scan the maquettes Scott created in order to come up with 3-D models. “Working from the external skin, Atkins developed an internal structural frame that would support the external cladding,” says Tim Burton, sales and marketing manager at SH Structures Limited. 

Scott created an internal frame to which he welded hundreds of small individual steel plates, giving the finished piece a degree of transparency, Burton says. The sculptures were then galvanized, giving them an initial shiny appearance. He added it was challenging to find a method to recreate this technique on a grander scale.

Fabrication breakdown

Going from smaller models to large-scale sculptures is where SH Structures, located in the U.K., came in, experienced with challenging fabrication projects.

On the much larger versions, fabricators used 6 mm-thick grade 316 stainless steel sheets which were uniquely laser-cut to give the impression of a larger number of panels while retaining the open effect of the models, says Burton. 

The skin of the horses is made from grade 316 stainless steel with an unpolished mill finish. Inside, the tubular skeleton is made from grade 355 CHS sections from Tata Steel. 

“The mild steel tubular sections were the obvious choice to provide a cost effective solution to creating such a complex shape of this scale,” Burton says.

A tubular structure was chosen because designers and engineers felt it would be more economical, versus a series of trusses and horizontal diaphragms.

According to Burton, SH Structures’ facility is not like conventional fabricators’ in that numerous jigs were needed. Drawings for jigs were produced by SH Structures’ 3-D CAD operators and fabricators and welders built the structures in stages, creating large sub-assemblies. 

“Welding the thousands of uniquely positioned brackets correctly takes great skill and it was sometimes physically hard to gain access to carry out the welds,” Burton says. “But all these difficulties were overcome and out of 34,000 pieces, only a handful needed any on-site modifications.”

Sitting on the eastern end of the Forth and Clyde canals, running through Helix park, “The Kelpies will serve as a gateway to the canal as well as being a major tourist attraction for the Falkirk area.” FFJ

The Kelpies from The Helix on Vimeo.