Specifications

68
5.8.8 Chain coupling and swivel
The Waverider buoys are fitted with a 5 Kg chain coupling attached to the mooring eye. This
provides stability when only a small vertical mooring force is present, e.g. for a free floating
buoy or a buoy moored in shallow water. Without chain coupling and when broken adrift, large
pitch and roll amplitudes could cause irreparable damage to the stabilized platform. Pitch and
roll will not damage a DWR-G, nevertheless the chain coupling is beneficial for reducing pitch-
roll motion of the buoy.
In the case of accelerometer based buoys the chain coupling incorporates a swivel at the
lower chain end that will prevent the buoy from spinning due to the mooring. As the DWR-G
GPS sensor is insensitive to spinning a swivel is not present.
Two chain thicknesses exist: 20 mm chain (WR-SG and DWR-MkIII) and 16 mm chain
(DWR-G). The chain ends or swivel are connected directly to the mooring eye and the rubber
cord terminal by 12 mm shackles with M12 bolt and nut, blocked by a 2x32 mm split pin. Chain
coupling, swivel, shackle, bolt, nut and split pin are all made of stainless steel AISI316 and are
delivered assembled to the buoy.
When the standard stainless steel chain is used together with a Cunifer hull, it must be
isolated by means of a Celoron block to prevent electrolytic corrosion, see Figure 5.8.5.
Figure 5.8.5.Mounting illustrations of a chain coupling for
(a)AISI 316 hull and (b) Cunifer 10 hull.