Going For Broke on Ramsay's Extension

This week Coracle Oracle The Friendly Bay Chronicle harbour historian Graeme Ferris tells us about the breakwater in Oamaru harbour.

Our crumbling harbour breakwater is often the topic of media speculation, even if only regarding the vast sums of money both the original Harbour Board, and since we were designated a closed port, the Waitaki District Council, have poured into this conspicuous local landmark.

On the seaward side of what was originally defined as our South East Wall, a decaying protrusion officially known as the Ramsay Extension, and now a crumbling heap of soft quarry rock and rubble, just seaward about where the northern end of the breakwater raising finishes.

Just why this disintegrating piece of engineering is named Ramsey's Extension and not William's, Furkert's, La Roche's, or even Leggo's extension is unclear for all were engineers or professors of some standing, and all, over a period from 1914 to 1938, were involved in the design and structure of this elusive breakwater extension. Captain Ramsey was the Oamaru harbour master from 1896 to 1922 and nearly always when mention is made about this money-munching breakwater add-on, his name comes to the fore, almost as if he was solely responsible for the unfortunate extension design.

The single and only need for this extension off the existing breakwater was to form a lee, an area of calm water, to enable the dredging of our harbour approaches to be carried out. This dredging had become essential to the future of our harbour as cargo vessels were becoming larger, therefore deeper, and the harbour approaches were at that time actually shallower than the dredged inner harbour.

The eventual outcome would probably have been no different, but when the extension work finally proceeded, it was constructed at a different angle and started from a different location than the several detailed plans had originally indicated.

The designed length also became something of a lottery, starting as 1,750 ft. (533 m) in 1914 and modified by various engineers over the years to about half that length. When work eventually ceased in 1944 with the outer end sealing of Ramsey's Extension, it had reached a total length of only 365 ft. (111 m), approx. one fifth of the original designed length. Just imagine the vast hole there would have been in the Harbour Board's quarry if the original length had somehow been achieved.

By 1945 the Harbour Board's engineers conceded that this expensive protrusion to our breakwater was a total disaster and was actually placing considerable stress on the immediate shoreward section of the main structure and also causing severe shoaling on the extension's northern side, the very area the original proposal had intended for deepening. The passage of time has shown this 1945 reasoning to be absolutely correct but long forgotten.

In the year 2007 we are poised to have contracts let by the local Council to reinforce and retain the remnants of this relic from our past.

Graeme Ferris