The Caterpillar side-boom tractor, or pipe layer, was an indispensable machine on the trans-Alaska pipeline, allowing teams of operators to raise and lower sections of pipe. The counter-weight opposite the boom could be extended to keep the machine from tipping over.
T
he pipeline took just over three years to build. Workers received medallions marking the end of construction in June 1977.
During construction of the pipeline, many welders cut crude maps of Alaska from discarded pieces of mainline pipe. Since then, fold artisans have continued to produce these steel sculptures, which have become popular souvenirs.