Althon were asked to quote for 18 Headwalls specified as being cast in-situ on the Bexhill to Hastings Link Road. There were three different designs for concrete pipework ranging from 450mm to 600mm internal diameter.
Types A and B were 3600mm wide x 3800mm long x up to 1500mm back wall height and therefore we couldn’t accommodate by modifying one of our standard designs. The Type A Headwall was quite straight forward with just a Penstock and water cushion but the Type B Headwall had a penstock, a chamber directly in front of the back wall with an Orifice Plate leading to the Apron and a Water Cushion cast across the front of the Apron.
The Type A Headwalls were cast in two halves with a stitch joint and the Type B Headwalls (pictured) were cast in 3 parts again with a stitch joint for casting in-situ on site. The Type C Headwalls were 2200mm wide x 2000mm long x 1500mm high and it was decided to produce these as a bespoke item as well. These were produced in two parts with the Water Cushion/Toe being joined to the main unit using Dowels and high strength non-shrink grout.