The Queensland branch of The Australian Hovercraft Federation held a planning meeting on Tuesday, 18th October 2011, at the RC primary school, 350 Mortimer Road, Acacia Ridge.
Visitors for the evening were Rita Chaffey, Kerri Audsley and Bill Russell.
Distinguished guest - Bill Baker from Banbury, Oxon in the UK.
Cruise report - Muriel Street, Redland Bay - Saturday 1st October 2011.
Peter, Elaine, Anna Marie & Thomas Venn - Turbo TP6 powered by a Subaru 1800.
Arthur & Judy Stead - Revtech Renegade powered by a 20hp Honda.
Des Goss - Simple Cyclone powered by a PE485 Yamaha 2 stroke.
David Venn, Bill Toppin & Bow the dog - White Expo Turbo powered by a 51hp PE485 Yamaha.
Steven Odgaard & Rita Chaffey - Blue Expo Turbo powered by a 51hp Yamaha PE485.
Phillip Audsley visited with 2 workmates Suresh Ghuge and his two sons Ojas and Ayush, and Keith Doyle and his sons Emmet and Ryan. Peter and Des shared in taking the visitors for rides along the Redland Bay Channel around 10:00 am.
David Venn initially tried the Yellow Hoverjet but the wind condition was a little too strong for this light weight craft, so David and Bill travelled with Peter for the first leg of the cruise. We set off along the Redland Bay Channel at 11:00 am and travelled east along the Logan River and out to Russell Island near the rocks with cardinal markers. We met Stephen Venn here who delivered the white Expo Turbo to the boat ramp and David Venn and Bill Toppin swapped over to this extra craft in place of the Hoverjet left behind at Muriel Street. We then travelled through the Cobby Cobby Passage and south past the slipping sands and Short Island. We rounded Stingaree Island and headed towards the Jumpinpin bar. Had a look at the Pacific Ocean briefly and then set up a picnic spot on South Stradbroke Island at 12:00 pm. We had a nice relaxing picnic under the shade of coastal she-oak trees by a picturesque sandy lagoon.
We packed up and headed off at 1:30 pm but trouble began to brew. The white Expo Turbo blew a fan on the beach when a stud dislodged and was drawn into the duct. We planned to go straight back to Redland Bay and swap fans with the blue Expo Turbo so that Peter could return to fix the white craft. Sounds like a good recovery plan, but it was not to be quite so simple. Bill Toppin volunteered to stay with the white craft and he was warned that it could take 2 or 3 hours.
Arthur and Judy Stead struggled to stay above hump speed as they crossed the channel towards Crusoe Island. Des stopped on the point and waited while Steven and Rita tried to stay with Peter and Elaine. The pistons melted in the blue Expo Turbo and as we settled in the water almost to the Short Island channel intersection, the swift current began to carry us straight towards the open Ocean. Luckily we were able to paddle the stricken craft onto a mud shelf on Crusoe Island. Des Goss with Judy Stead and Arthur Stead now caught up and Arthur lent me a spark plug spanner.
Cleaning the plugs made no difference. No compression on front cylinder. Des with Judy headed off. The Simple Cyclone was working hard to progress into the strong westerly wind. The Revtech Renegade managed a little better without a passenger. Rita and I could only leave our blue Turbo on the mudshelf for 20 minutes as there was a vertical drop of 2 metres at low tide. We refloated and moved back in on a sandy beach 50 metres further east.
Des was now carrying Judy in the Simple Cyclone and Arthur was able to proceed safely in the Revtech Renegade. Des however had a slight pulley misalignment and under the heavy load condition caused by running at maximum power into a strong wind, his thrust fan drive belt began to shred. Des settled down under the Russell Island Power lines at which point Judy managed to draw the attention of a passing boat. She explained the difficulty and the kind fisherman took her onboard his boat and then dropped her back at thew boat ramp in Redland Bay Channel just as Arthur was refueling the Renegade to head out and look for Des. Meanwhile Des had made it as far as Little Rocky Point, and even though he was only half way home, at least he was back on the main land.
Peter Venn realised that he was not going to make it home for his fuel was running low, so he had to land on Russell Island and drop off his passengers. Elaine rang for the safety boat and Don Venn quickly prepared for a rescue. Elaine, David, Anna-Marie, Thomas and Bow made it back to the mainland via the Redland Bay ferry. After having concern with a van with a flat battery parked near the ferry ticket office, eventually Judy Stead was able to drive north to the Redland Bay Marina to pick them up in her car and bring them home to base at Muriel Street.
Peter Venn made it home travelling alone and then set about to refuel, pack tools and rendezvous with Don Venn for the retrieval of 3 craft. Don Venn was already on his way by car and trailer to Muriel Street, and Arthur had decided to return to Rocky Point to stay with Des Goss.
Within 2 hours, Peter in the Turbo TP6 and Don Venn in his half cab boat were back at the Jumpinpin Bar. Firstly he unbolted my fan and then we cut the rear skirt segments in preparation for the long tow home. We pushed the Blue Expo Turbo back into the channel and hooked it up to Don’s boat. Peter then ferried Steven and Rita out to the boat and Don began to tow us home. Peter and David went east to where Bill Toppin was waiting with the white Expo Turbo. They took about 25 minutes to replace the fan. David took the white Turbo home and Bill Toppin travelled as passenger in the Turbo TP6 with Peter Venn.
On board Don’s boat, it was a slow trip but we managed a speed of 8 kph by the GPS which was against the flow of the tide. Even at this slow speed the outboard fuel consumption was poor. We reached calm water near the slipping sands and carefully navigated through the Cobby Cobby passage. When we reached the power lines, Arthur called us up and gave us the location of Des Goss who also needed a tow. We headed west south west and found them safely on the shore at Little Rocky Point, not far from the Sugar Mill. Des was able to start his Simple Cyclone and came out to tie up behind the blue Expo Turbo with a vee line. We circled around and Des climbed aboard the boat. We were now set for a slow tow back to the Logan River and upstream to Muriel Street.
To hold the boat on course we had to maintain at least 8 kph or 6 kph when the wind gusts eased, but we found that the Simple Cyclone was only safe to be towed at less than 4 kph. A very difficult choice arose. Travel too slowly and we lost steerage. Travel too quickly and we risk filling the Simple Cyclone with sea water. No choice. The boat was blown east toward a mudflat so Don raised the outboard leg and powered back into the deeper channel at 6 kph. We then saw the Simple Cyclone fill with water from the engine bay. It began to wallow and then nose dived and rolled below the water line. Paddles, seat cushions and luggage in plastic bags floated away, but as we cut our speed the hull at least rolled back right side up due to the sandwich foam floatation in the fan duct. We circled around and pulled in the floating debris and came along side the swamped hull.
Des reached in and turned on the 2 bilge pumps. We had to try and hold the back of the craft up to prevent waves rolling into the hull. This was not successful. We had no choice but to let it go and continue to tow it full of water. We took another hour just to travel 2 kilometres north to Long Island. The large power line masts and 2 channel beacons became obstacles as the wind gusts and strong tidal current continued to blow us off our heading. At 7:00 pm it was dark and the temperature cooled. Rita and Des began to feel cold and uncomfortable. Don had large fishing overcoats stored on board which helped to keep them warm and dry.
We run aground at the entrance to the Logan River and we had no choice but to sit and wait for the tide to turn. Peter and David returned in the Turbo TP6 with a large petrol powered pump and a 38mm suction hose. They managed to pump out the Cyclone but the pump developed a leak and some of this sea water began to flood the compartment in the TP6. David climbed in the Cyclone and continued to bail with a rectangular scoop. He then climbed back onto the TP6 and manoeuvring behind the Cyclone managed to cut the rear fingers. Although the current was still flowing out, the water level began to rise at 8:30 pm and we set off again. The outboard had churned a lot of mud and the over heating alarm sounded briefly.It took another hour to travel up the Loan River to Redbill Island where we turned into Lagoon Passage and finally pulled up in front of the boat ramp at 9:30 pm.
The tide was very low, so even disembarking the pontoon meant climbing a tall ladder in the dark, and retrieving 4 vessels up the long steep boat ramp took nearly an hour and a half. It was great to finally have all souls and craft home on dry ground. We made a contribution to Don Venn for his fuel, wear and tear and thanked him for his speed in action to come to our rescue.
Out in the workshop, the first priority was the clean up of the Simply Cyclone. We poured rain water into the engine through the spark plug holes and turned the engine over by hand to flush out the sea water. Peter said that to avoid bearing failure, the first 72 hours are crucial. Next we flushed the engine with odourless kerosene. Peter had about 50 gallons of kero which he uses in his Salvinia Natans and Hyacinth eradication formula.
Although it was now very late, everyone stayed around and we discussed the various ways in which people returned to Muriel Street from that lovely picnic spot by the sandy Casuarina and Pandanus lined Lagoon on South Stradbroke Island at 12:00 pm Saturday.
We all departed by 2:00 am Sunday.
On Sunday, during the daylight, Peter worked on the Yamaha with the burnt pistons and found a loose pulley adjustment on the belt driven cooling fan to be the main contributing factor. He also found 2 reconditioned pistons and barrels to use as spare parts to quickly rebuild the blue craft in order to have it back in action for commuter work to Russell Island where younger members of the family now live.
Des Goss came back to work on his engine and Steven and Rita returned in the afternoon to lend a hand. We reassembled the thrust unit and fitted it back into the hull. By 7:00 pm it was all wired up for the test run. I am happy to report that it started and ran and that Des went home delighted with the thought that the Simple Cyclone is restored to cruise another day.
We had the pleasure of a distinguished overseas guest:- Bill Baker from Banbury, Oxon in the UK.
Bill shared some of his experiences with craft breakdown and recovery on the Thames, in the Solent and at Southhampton Waters. One method of recovery is to use a 3hp outboard engine on the nose. He once tried propelling a hovercraft with a soil rig well midship, but found it impossible to steer the small outboard engine in this manner. Another retrieval method was to tightly lash a stricken craft with between two good craft with rope and poles. Travelling 3 abreast, a small craft can be carried back to shore.
An interesting river in Ireland is the Shannon. It is a glacial river and has very few places to land due to the steep banks. Bill explained that when towing a craft in water, the tow hitch needs to be down near the leading edge of the floor line rather than above the deck on the nose. A craft with a single drag flap does not need to have its rear segments cut whereas a multi drag panelled rear skirt does need to be cut or released to prevent water scooping back into the fan duct and engine bay. Sometimes people buy racing craft with only 200mm hull heights and then get into difficulty when they go cruising in rough open water. Bill described his 3 seater 4 seater and 6 seater hovercraft models.
He gave us some good technical tips on cushion pressure, craft thrust to weight ratios and engine choice. eg Suzuki GSXR 650cc 750cc or 1000cc. Engine revs up to 18,000 rpm are attained in racing craft with thrust to weight ratio in the order of 3:2. He gave us a report on 2 fan manufacturers who had split from the Danish fan company Multiwing with the new companies WingFan and Hascon setting up in Germany. Multiwing in Australia is not particularly interested in ACV applications however WingFan are very pleased to assist as they are keen to compete for market share.
Bill was shown a colour magazine from the QSH archive dated 1st March 1975 called World of Wonder with an artist’s painting of “Join the Hovernauts On page 6”. Bill was able to identify the race team members saying this painting was done from an actual photograph of racing in the HCGB. He identified Nigel Beale, Alan Bleout, Graham Nutt and Barry Oakley in the old magazine cover. Back then craft were constructed by mechanically minded youngsters for between 125 and 500 pounds.
Bill and son Rupert have competed in many British European and World title race events and have produced some of the finest light hovercraft designs in the world. Bill told us that the club in the UK has approximately 600 members however there has been a split with some cruising members with Sevtech craft preferring to branch out on their own.
The next club cruise will be held on Saturday 5th November 2011 at Muriel Street Redland Bay.
Meet at 9:00 am at Peter Venn's place at 96 Muriel St, Redland Bay for a launch into the Redland Bay Channel. This will be a safety training session in using a recovery vessel to tow various craft on tow mats in fast flowing tidal current.
Bring along a tow mat to try out with your ACV.
The air cushion vehicle does not need to be in working order to participate.
This is more a test on tow mat tailoring and hitch technique.
The next club meeting will be held on Tuesday 15th November 2011 at 7:30pm.