, low tide, looking upstream. Starlings may form part of a
buttress for the vertical load of the bridge piers, so would typically be symmetrical. Other symmetrical starlings may be used on tidal stretches of rivers because of bi-directional flow, requiring dual cutwaters; at low tide,
Old Wye Bridge, Chepstow, on the Welsh border, can be seen to have cutwaters on both ends of the piers and their foundations. Cutwaters may also be provided downstream to reduce riverbed
scour. Other starlings may be asymmetrical, with only an upstream cutwater, the downstream end being flat or rounded. The starling has a sharpened or curved extreme, sometimes called the nose. The cutwater may be of concrete or masonry, but is often capped with a steel angle to resist abrasion, focusing force at a single point to fracture floating pieces of ice striking the pier. In cold climates, the starling is typically sloped by about 20 to 45° from vertical, so current pushing against part-submerged ice tends to lift and shear it; this can be known as a
starkwater. This is distinct from a sloping top to shed the rain. On a narrow bridge, a cutwater shape can be carried up to the top of the parapet, to provide a pedestrian refuge. , Connecticut: starlings on the bridge piers and at each end of the
swing span (the fence-like structures around the piers are pile-supported
bridge fenders). , Derbyshire. == See also ==