Showing posts from 2008.
End of Season -Start of Major Works
Karina, Chris and Simon each had our last hover of the year today, at the West Reservoir. We have decided to take SBW to the workshop for some experimental modifications. Our motivation is as much to use the craft as a test-vehicle for the ideas as much as in the hope that they will make it perform better. One is a device to even out the cyclic variations in torque from pedalling, the other is an attempt to control the trim of the craft. Will they both work ? Don't know yet. But you've got to be in it to win it.
Posted on [17th Nov 2008]
Gratitude to our advisors
Someone asked today "Did you invent it ?".
No, Christopher Cockerell invented it, we just designed this one. His inventing enabled us.
We are also grateful for all the various advice we have received from hovercraft experts and others that have helped us on our way.
In particular, recently, thanks are due to Malcolm Whapshott for information to improve the efficiency of our propeller, and to Rob McConnell for suggestions that may help us in solving the pitch-trim problems.
We are always open to listening.
But in case you are thinking of suggesting
"Why don't you take a long walk on a short pier ?"
Well, we have done that already , lots of times.
Posted on [27th Oct 2008]
We continue with a series of tests.
Today we were experimenting with whether the skirt-fingers would still work without each having an individual air-feed from the higher-pressure bag.
So, we blocked up five adjacent vents - the relevant fingers still worked.
Then we made a game of it. Simon got on board and I tried to push one of the fingers out of shape while he was hovering. It sprang straight back. Then we swopped places. The hoverer always won.
Posted on [12th Oct 2008]
We still carry on
Yes we still carry on even though on Sunday 7th Sep we had our worst damge incident yet. We had had a good day, then when packing away, it was lifted when it was partially derigged. Crack ! The steering horn was broken.
During the week, we repaired it and on Sunday 14th, we were back hovering again.
There was an opportunity to give Sue from Scotland her first hover, and Karina, Simon, Chris and Pouha all had a hover.
Posted on [15th Sep 2008]
Carry on at the Reservoir
Today we launched it as a boat. Not slipping down off a beach or ramp like any other hovercraft: this time we put it into the water empty off a yacht-jetty, let it float, then Simon stepped in. Actually this is how we had envisaged trip initiation at the design-stage. But we have never done it like this before. How did it go ?
Putting it in was easy. Stepping in was easy. Stepping out was easy. But getting SBW up onto the jetty was a frightful task. This is because the bag had a lot of weight of water in it. It took four of us, Karina, Sidique, Simon and Chris, and we were lucky not to damage it on the jetty-edge.
We did another test. We taped temporary extensions to the trailing edge of the fan. Would a wider fan blade make hovering easier ? First impression was that the extensions made it slightly harder, but not much. Another series of tests was made with three different people. We all agreed that the extensions made hovering harder.
Also, we are working on improving the water-drainage from the bag. This isn't for when you're trying to lift it up onto a jetty, this is for when you've been floating and want to start hovering. The water does drain out - eventually. We will add more holes to make it faster.
We still have a succession of minor breakages. But nothing that masking tape can't be a temporary repair to. Today the propeller tips hit the water surface and this scarred them locally - but the propeller still propels and the hovercraft still hovers.
We just want it to propel faster and further with less effort, and that is what we are continuing to work towards.
Join us at the reservoir if you are interested.
Posted on [31st Aug 2008]
At the IHPVA World Champs, Bentwaters 2008
We had a fantastic time, the weather was half-decent some of the time, wish you had been there.
Claudia Goodman became our first lady passenger. (See photo in our gallery).
We went onto the tidal creek at Orford. The UFOs which are said to abound in this area tolerated us. Perhaps they thought we were one of them !
Simon made some good straight runs on the tarmac, and hectic-looking swivel turns which impressed the crowds.
Several event-goers helped with the handling and we had invaluable assistance particularly from Fred Ball of the AYRS, Ian Fardoe of the BHPC and Nigel and Carole Cliffe.
Most people turned up at the event with streamline bicycles, some with two wheels, some with three. Ours, of course, has no wheels, but the most amazing thing there had one wheel. Well, effectively, WAS one wheel. You ride inside it - incredible.
Nigel, the WHEEL crew, and others also hovered SBW themselves.
Posted on [18th Aug 2008]
Story on this Website
Just added at the bottom of the Technical section is a narrative of the project which covers all aspects including the technical. ( Scroll on down below Weight Analysis ).
We are continuing to operate on Sundays at the reservoir and are firming up plans for the trip to the World Champs on August 16th and 17th. Let us know if you want to join us at either of these places.
Last Sunday, Karina Townsend became airborne in SBW, and Paul Standeven, Jonathan Roper, Simon Ward and Chris Roper continued with adjustments to the skirt. This involves someone onboard pedalling while the rest of us observe the effect of the last adjustment etc. We will continue with this to make it easier to keep up and more stable.
Posted on [18th Jul 2008]
Forward progress over land seems a lot easier with the new fingers.
We did a few more tests in the street, but after a while we thought that we were ready to test it, with the new fingers, on water.
So, today, Sunday 29th June, Paul and Damien and Geoffrey and Simon and Chris loaded the craft onto the van and we set off for Stoke Newington reservoir.
We are getting quicker at rigging and derigging and we had it all set up, but the wind was gusting in a rather threatening way, and we opted to stay on the bank.
However, Paul was able to make his first static hover. It always good to see someone new becoming airborne just by pedalling.
Let us know if you want to be involved.
Have you seen the latest additions to the Gallery on this site and to the Technical section where we show the weight of the craft and of its various components. By comparison our close namesake Steamboat Willie is 80 feet long with a 16-foot beam and weighs approximately 70000 pounds.
Posted on [29th Jun 2008]
Airborne again !
O.K., so its only been three months since we were last hovering. And the new orange fingers that we have added are the same shape as the old plastic ones that they replaced.
So, this afternoon when the new fingers worked just fine, then I suppose it would have been reasonable to say, "Well , so they should, what's the big deal".
But it was a thrill. I, Chris, was first up and I couldn't wait to get out of the craft so that I could see them working from outside.
Margaret Barnes, Simon Ward and myself had nearly finished fitting the skirt back on when we were joined by Etienne Gilfillan.
Etienne helped us put the last few sealing tapes on and then made a movie,
see "Orange Fingers Test " in "Gallery".
Plans now are to finish testing out the various modifications that we have made. This will be done on land and on a North London reservoir. Then in August we will be at the IHPVA World Championships ( see events).
Posted on [14th Jun 2008]
We can now begin to see the end of the series of repairs and modifications.
A whole new set of fingers have been made and sewn on, same shape as before but made of a tougher material.
We discovered several damaged areas in the panelling of the perimeter frame. This panelling has a weight of 0.006 pounds per square inch, about 1 ounce per square foot or 4 grams per square decimeter or the weight of five sheets of paper. So, considering it gets bashed by waves while helping support a person's weight, it has stood up pretty well. There was one set of three dents which we reckon are the "fingerprints" of three pebbles caused by a rough beach landing. These have now been patched.
Also several other small modifications are underway, including splash-guards to protect the chain and sprockets from spray and waves. ( We had some trouble from corrosion last summer.)
Hopefully we will be re-fitting the bag in a week or two. Then we will be hovering again.
Posted on [25th May 2008]
We are in the process of giving the hovercraft a jolly good spring clean.
The transmission has been completely stripped down. The chains have been soaked in oil. We are cleaning bearings and any moving part. We have tipped quite a lot of sand out of corners where it has lodged.
Also the fingers , the lower decimeter (4 inches) of the skirt, is being completely renewed with a tougher material than before.
We are taking the opportunity of weighing all the components and the ensuing data will soon be up on the technical section of this site.
We are looking forward to having it all back together again and hovering.
Posted on [27th Apr 2008]
One World , One Dream, Free Tibet
To bag the Olympics Beijing promised there would be press freedom 'all over China'. The gullible International Olympic Committee believed them but, for many, the outcome was never in doubt. The Olympic press freedoms will never apply in Tibet - unless we continue to take action now.
An atmosphere of repression and censorship continues to surround the media and free-flow of information in China. Local Chinese journalists remain under constant threat. Even the global cyber players caved in. Try googling in China for Taiwan, Tiananmen or Tibet.
The opportunity that the Olympics brings to foreign journalists to interview individuals freely all over China has been denied in Tibet. Again the Tibetans have been betrayed with another promise broken in the full sight of the international community. Why does Beijing want to hide Tibet from the world?
You can help by putting something like this on YOUR site. Beijing can't censor us all. Some of the truth will get through.
Posted on [11th Apr 2008]
Climbing Out of the Sea.
We had been waiting for a day which had calm winds. The other requirement
was that enough of us would be free from our other engagements to be able to
operate SBW. Wednesday the 20th of Feb was such a day.
After adding some bottom flaps to the aft fingers, Malcolm, Chris and Simon
took SBW across the road onto the beach. The tide was out and a glorious
stretch of smooth sand was available to hover over on this fine windless
day, with the sea as smooth as glass.
We carried SBW over the pebbles onto the sand with high hopes that now it
would really show what it could do. At last we would really pedal down the
beach, (rather than a slipway), and onto the surface of the water.
(Slipways we can do, see video)
Even though it was February, a cold month in this country, there were a couple of dozen beach-strollers who stopped to watch as we set the pedal powered
hovercraft down pointing boldly out towards the ocean.
How far would we get ?
We didn't even get up off the sand.
Not properly. That craft with those fingers just couldn't cope with wet
sand. Simon as pilot was only just hovering and Malcolm and Chris gave the craft
some assistance tugging it forward. Reluctantly it proceeded onto the water.
When Simon returned back onto the beach, fairly soon, we could see that
most of the fingers had been ripped to shreds.
There are some surfaces that SBW likes, some it can cope with and the
others. Wet sand, we discovered, was one of the others.
However we took the opportunity to test out what would happen if you
stopped pedalling when at sea. This could happen if you ran out of puff, or
if part of the mechanism were to malfunction.
So with the propeller removed, Simon climbed aboard and hovered, and Chris
pushed SBW out onto the water, until with SBW hovering above, Chris was up
to his knees. The Simon stopped pedalling. Water was seen to seep up near
the keel. But the perimeter float kept the craft bouyant as intended. Simon
started pedalling again. To our amazement and delight it went up to hovering
as quickly and easily as at anytime. We didn't believe it. "It can't really
have got any water in the bag", we thought. So we did it again. This time
Malcolm timed us, and it was floating for over a minute. Again, it readily
climbed up out of the water just as before. Chris could see through the fan
inlet that there was still a little water in the bag, but this was soon
expelled through the vents.
We continue to be surprised by what SBW can do and what it can't do.
The day's findings :-
We can climb out of the sea, but we can't climb off wet sand.
Tests and development continue.
Posted on [22nd Feb 2008]
Second Passenger, & Tarpaulin tested.
Michael Milburn, seen watching in earlier pictures, had his chance to climb aboard
on Sunday 3rd Feb 2008. Chris found that Michael is appreciably heavier than
Ethan and was just about at his physical limit on a third take-off. We were
helping to make a TV documentary and the producer said "Just one more time".
Chris needed to take a few deep breaths before he could oblige. Michael
stayed steady, and performed well, climbing in and out carefully with help
from his father Ian Milburn. Ethan has to stretch to reach the pilot's shoulders.
The two lads represent the limits of size for a passenger, (on a craft that
was designed for only one).
Even without a passenger, hovering SBW over grass is also hard work. This
is compared with water or a smooth surface. We had been thinking that maybe
pegging a tarpaulin down like a big groundsheet might produce a surface over
which we could hover. We tested this, in quite a strong wind, and found that
the system works. We will now be acquiring a bigger, or several, tarpaulins
ready to give displays at festivals.
Posted on [6th Feb 2008]
Automatic Pitch Control development crisis.
Controlling the pitch of the propeller adds to the work-load of the pilot
and we have been considering adding an automatic pitch control system. On
the SBW, the fan revs must not drop below a required minimum to keep the
craft hovering. Any power you produce in excess of this can be used to drive
the propeller. Ideally, you will keep pedalling at the same speed, harder,
but not faster, and definitely not slower. At the moment, this is arranged
by you operating the pitch control with your left-hand. But, if this is made
automatic, then you will be able to just pedal, and if you pedal harder then
pitch will be increased, (by the system), and you will go forward. We
assumed that if the pitch is too high such that effort required from pilot
becomes too high then the revs become low, and the pressure in the bag will
drop, ( and vice-versa). So, we started to design a device that would
measure the pressure in the bag and, through a linkage, pull on the pitch
control cable until the pressure was nominal. We even started to make a
mock-up, (full-size-model), of the linkage mechanism. There would be a
"trim" control that the pilot could use to effectively decide what the
current "nominal" is.
Then Geoffrey, Simon and Chris did some tests on how much the bag-pressure
varies with pedalling rate. The results indicated that the device would
probably not work, at least not as currently envisaged.
Is there anyone out there who can advise us ?
Do you know of an effective, practical way of arranging a
Have you any ideas for a totally different way of doing it ?
Or, maybe, just a simple tweak which would make our current design work ?
Forget those big Sudokus, this is a real problem. One we don't know the
Posted on [6th Feb 2008]
Kenny Bradley of California has sent us a solution to the 36 by 36 Sudoku.
He thereby becomes the winner.
If anyone else had nearly solved it, send us your solution by 17th Jan, and
we will acknowledge you as a runner-up. Then we will publish the solution.
Posted on [3rd Jan 2008]