I used 55 gal food grade drums 3 years ago and they do not leak. You just have to use a silicone sealer when screwing on the caps. I paid $15 each for 18 white barrels from someone I found on craigslist. I used your plans when building my dock and they were great. But a storm this winter separated my gangway from the shore and I need to do a repair but I don't remember how to set it up. Unfortunately, the images you originally posted do not reload and it would be most appreciated it you could repost you photo of how you attached the gangway at the shore end. Thanks, Larry