Talk:Diving in South Australia/Rapid Bay Jetty

Photos

Nice article, I have added a bit from my logbook and photos, and there are more photos at https://commons.wikimedia.org/wiki/Category:Dive_site_Rapid_Bay_Jetty I have not spent much effort on formatting - you may want to add, delete or rearrange photos or rearrange the page to look better. Article is definitely usable, probably near guide quality. • • • Peter (Southwood) ^(talk): 09:52, 22 January 2015 (UTC)

Thanks, Peter. Cowdy001 (talk) 20:22, 22 January 2015 (UTC)

Structure of the jetty

Hi everyone, I removed the following text from the page because it is incorrect:"Large disused jetty with steel universal column section piles and supporting diagonal braces. Some of the structural steel has corroded away, leaving the piles hanging from the main structure, with relatively jagged ends." The old jetty is principally timber. The piles were all concrete-encased in the late 1930s to protect against teredo worm attack while the wharf section (& the immediate section of jetty) remained unprotected until the 1950s which it was rebuilt in steel. Subsequent repairs to the section of the jetty where concrete encasing was used, has used steel sections to reinforce and replace failed timber piles. Please refer the following image which shows the rotted timber structure - http://www.benandcamera.com/diving/adelaide-south-australian-dive-sites/rapid-bay/ and the following article about the old jetty's history where the construction system is discussed - http://www.rapidbayjetty.org/history.htm. Regards Cowdy001 (talk) 05:17, 23 January 2015 (UTC)

Hi Cowdy. There may well be concrete encased wooden piles, but definitely also steel universal column (I-beam with wide flanges) piles, and some of the diagonal braces are wasted away and no longer continuous. I will take a look and see if I have any more photos to show this. Cheers, • • • Peter (Southwood) ^(talk): 09:35, 23 January 2015 (UTC)

I have photo transects from the T junction to the east, west and south, all along rows of piles, for 50m in each case, and where you can see the structure through the overgrowth, it is more often than not steel U. column. There are a few which may be concrete encased wood, and the concrete would be flat sided in all those cases. Cheers, • • • Peter (Southwood) ^(talk): 09:46, 23 January 2015 (UTC)

The photo of the stars shows a distinct change in structure at the kink in the main jetty. To the landward side the piles are closely spaced and appear to be round in section, ie, wood, but beyond the kink they are much further apart, and look like steel. I also have some rather blurred photos of the underside of the jetty between the kink and the Tee which show steel section beams and steel section pile tops and braces. • • • Peter (Southwood) ^(talk): 09:54, 23 January 2015 (UTC)

On further inspection I see that it is mostly, if not all wooden braces that are wasted through near the waterline. Some are visible in my photo and also in the site in your link. I remember swimming past them on the surface and having to avoid the sharp ends. • • • Peter (Southwood) ^(talk): 10:12, 23 January 2015 (UTC)