For this unique entrance to the 33rd Street Penn Station entrance in New York City, the architect designed an inward facing angled elliptical opening at street level. To be able to construct this, both the top and the bottom sides of the angled concrete ellipse needed to be formed at the same time with every foot of the form changing in size and shape. The 31 individual forms were constructed of 1.35 lb density EPS and coated with a 3/16” polyurethane coating, both for strength and to provide a smooth surface for the concrete. The forms were backed by ¾” plywood for attaching to the contractors’ horizontal base form. Everything fit perfectly and the concrete installation went according to plan.
