The 'tricks of the trade' column...

[A. Berk]

Safety first- pier's undermined (that's why you're there) so, there's always the chance that something could come rolling out at you or your umbilical.

Yeah, like the bag for instance if it's too big and unmanagable - it may roll out over your hose - a situation that I saw happen to someone close to me once what a berk!

Its worth getting the sups to give your pneumo a fecking good blow every so often as grout can settle in there and block it like, er... like cement atually!

Broke

[diverstu]

One of the funniest things I've seen was a blow-hard who was laying a pea-gravel bed for pre-cast blocks- "up on you're slack?-NO. can you see the bucket?- JUST DUMP IT. He dumped about 4 tonnes in the same spot without watching it, and as the vis clears, we can see him following his umbilical...straight under the mountain of pea-gravel! we were rolling around the dive shack for a good 20 mins, as he tried to make on that nothing was wrong, and he was merely 'working hard' to rake the gravel down! Just as the site Foreman came in, we were scrabbling to get a video in the unit to record the class act, and he got free.
I believe that ex-miner later underwent corrective surgery to allow his true sexuality to blossom.

[A. Berk]

I got a bit cocky and figured I could get away with one big grout bag under a bridge. My mate Colin (RIP) had been in there previously and said it would be better to sew-up two or three smaller bags... I knew better

The bag (4m in length and as round as Susan Boyle) filled nicely, right up to the point where the stone work that was holding it in place gave way and it rolled out... like Schummaker in pole position! Luckily I wasn't wearing fins so it missed my feet but not my hose. The bag settled in the middle of the river at about 5m deep and left me with just enough hose to get my eyes above water. I could see the lads supping tea and the labourers dumping bags of Portland cement into the mixer... oh what to do - the embarassement Colin was stand-by diver and I eventually sommoned the courage to tell 'em to stop pumping and ask Colin to come in and help me cut 4 tons of grout off my hose

A. Berk

[diverstu]

Years ago, big void in the pier, funny design, horizontal concrete beams with a gap between them just wide enough for a (thin) diver to slip through. At low tide I was elected(!) to clamber in and place the bags. I'd done a couple, and the tide was coming in. the Bag was getting full, so I shouted up for them to stop pumping. No reply. Bag was getting really full. Shout. Nothing. Stitching starts to pop. I'm in the corner of a very small hole, trying to merge with the wall, LOUD shouting, then...BANG!
Never heard concrete go bang before, my ears hurt like hell, I'm covered in concrete. Bollocks.
Then I try to get out of the hole. Tides coming in...er, pretty fast, actually..erm, maybe if I twist this way...no. no, that's actually worse, and I'm fairly sure...yes, I'm stuck. I wonder how many scuba bottles we have in the van?....probably not 12 hours worth?

Luckily blind panic saw me through, and I got out, to an audience of blank looks and "eh? how do you mean it's not finished- the bloody tide's coming in you know?!"

Yes. I know.

[diverstu]

There must be something we haven't covered yet? anyone?

[A. Berk]

There must be something we haven't covered yet? anyone?

Absolutely - SANDMAN WHERE ARE YOU - can we have some concreting tips please?

orBek

[A. Berk]

OK, here's one... ULO grout support bags/matresses;



These are common in the ME and India and although easy to install they can get 'untidy' if you're not prepared. The bags come in various sizes and you should mark them all while on deck to give the diver a clear indication of their sizes. Also they can be a pain to place under a pipeline if the bottom is shitty or you have a current so use the loops specially placed along the bottom edges and run pre-cut lengths of scoffold pole through them. You can then roll the poles in towards each other to form something that look like one of those old military canvas stretchers. The diver can then simply slide the whole shebang under the pipe at the required location, clip the two securing tapes over the top of the pipe, roll it all open and start filling. The scaffold tubes will hold the base in place while you're filling an once you are happy with it you can slide them out to be sent bake to surface in the work- basket. Remember that the topside grout crew need 5-10 minute of notice to when you want grout so if you have 3 bags to install tell them to start mixing when you are installing #3. Once they start pumping grout watch the nozzle end, you'll get water first, then thin grout and then the heavy 'Guiness-like' billowing grout flow - time to stuff it in the bag. Keep an eye on the bag as it fills and when you get flow out of the top vents watch for the same flows and start tieing off the vents when you get heavy 'Guiness' flow and tell topside to stop pumping. Having a bunch of rags at hand is a good idea as when you pull out the filling nozzle the non-return inside may leak and a rag stuffed in the tube will sort it. Cable-ties are quicker and more effective in closing off the top vents than the factory installed peices of string. When doing an 'As-Built' survey remember that the position of the base of the bag means nothing to a Field Engineer who wants to know the total 'unsupported' length of pipeline, so always take your measurements to/from the point at which pipe and top edge of the bag physically meet. If you are air diving ask for a slight continous flow on you're pneumo while grouting 'cos grout can settle in there and block like only cement can. If you're in sat you can fit one of the wee plastic fitting caps loosely in to the pneumo end and give it a good blow-out every hour or so.

Berko

[bruno007]

Whats the best way to bung / fill a small hole or tear in a grout bag subsea ? We are currently grouting at the moment and the amount of holes in the bags is a joke; some holes are small enough to bung, but others beyond repair, and an awful lot of grout has gone to waist and bags slit open and hoisted back onboard ( Messy !!! )

We have been using rags to fill the leaks, but is there a better way.......?

Best Regards - Bruno007

[A. Berk]

Hi Bru... by the sound of it you have been given a bunch of rotten old bags and as we all know they can be bitches to deal with If they are that bad with big holes I dont think there is a 'formula' as such apart from doing the rag thing as you already are. The only thing I can suggest what should be done is get an industrial hand-held sewing machine on the job and sew up the large tares... or get new bags of course!

Stay safe Bunro and I'll see you in April... oh and regards to Mike and the lads

Bkore

[bruno007]

Thanks Bekro......

Yep.... looks like rotten old bags I guess, courtessey of .... ; or someone's been sat on them playing with a sharp knife ! ( Not I..... Honest ! ) lol

Will give the lads your regards and see you in April mate.....

Bruno007