Model Building Tarka II

The model for Tarka II was built in pretty much the same way as Tarka I, using frames and strip wood planking. I won't bore you with details again, but here are some pictures of the model in build.

Tank Testing (Take 1)

Its taken weeks of standing out in the freezing garage superglueing our fingers to thin plywood strips. We've gone through several trees and an entire beach worth of sand paper, but the model is finally ready.

Today we took it down to the towing tank at Southampton Solent University. Their tank is 60 meters long and allowed us to test (at an equivelent speed of 17 knots).

The model is fixed to a carriage that sits on rails via a post. The carriage can then be sent down the tank at precise speeds and the resistance of the model can be measured.



The model is sent down at a series of speeds, correcting the trim each run and then a resistance curve can be produced which will give the naked hull resistance of the boat at any speed. We can use this to estimate the amount of power required to reach certain speeds.

We ran tests in the sprint and endurance conditions and the data should prove invaluable to help us design the new boat.

Model Building Tarka I

We have been set the challenge of redesigning the hull for Team Tarka. The rules of the competition mean that the hull must be optimised to fit somewhere between being really efficient at low speeds (for the endurance event) and being really efficient at high speeds (sprint event). These two cases require a hullform with completely different features.

Before we start designing the new boat, we need to get a better idea of the performance of last years boat. We want to get some accurate data from some towing tank tests.

To do this, first we need to build a completely accurate scale model of last years hull.

We started by getting some frames (bulkheads) laser cut from 4mm thick marine grade plywood. These form the basis of the model and ensure that the shape of the hull is accurate.

The next challenge was to glue even thinner plywood (1.8mm) to the frames to form the hull of the boat. This took a suprising amount of time! Once the strips were glued on, they were faired - so much sanding...

The finished hull was then ready for a thin layer of GRP and painting - more sanding!

The boat then went on a major weight loss regime, losing most of the longitudinal (fore-aft) structure and all the bulkheads were cut down.

Team Tarka 2010 first meeting

After the long summer, team Tarka reconvened today to begin planning for the 2010 competition. Early days yet, but we have new people on board, a new team captain, Jon Burton, and much stronger links to the ship science group. It should be an exciting year ahead.

First date for the diary is the 20th October, when last year's team will give a talk at the IEEE student branch. See the IEEE site for more information.

Team Tarka featured on Eland "Reel Life" blog

Eland cables have added an entry to their reel life blog about team tarka, and the important part that Eland played in getting our boat ready for the competition.

Final Results

So, the end of Project Tarka has arrived with the following results today:

3rd place qualifying event
Winners : Teamwork Award
Winners: Best Score for a rookie team
Winners: Sportsmanship Award
Overall Place : 10th

We had three excellent sprint results today, with three consistent runs of 47s, 47s and 50s (with an experimental prop angle and not fully charged batteries). Karim drove very well under difficult conditions, and the boat looked great. Karim also now knows the new technical term "give it the beans!"...

Yesterday was a highlight, with the morning run a tactical error on the power management front leaving us short on battery power too early and 14 laps completed, but the second run was simply *outstanding*, with 17.75 laps completed and one of the best pieces of overall teamwork I've ever seen.

Dirk driving to a schedule superbly, Karim doing Telemetry and working really hard to get it working and then providing fantastic numbers, Rich on race tactics and superb radio, and myself on the Radio point on the dam overlooking the race and providing wind and race status to Dirk and the guys. The outcome was joint first in the standings in the Silver medal race, and a really exciting race, from being lapped early on, to a two hour chase of the leading boat which we caught up on the final minutes with the batteries giving out as the finish hooter went...it was fantastic...

From an engineering standpoint we had *no* problems with any of the engineering, and the boat was running on its limits all week - it could have not been run better. The best compliment paid was almost every team saying "we need to watch out for your guys next year".

Many thanks for all your help, hard work and commitment - and I hope we've done everyone proud with this rookie outing, exceeding my expectation. Getting into the top ten was a dream this year, but I didn't really dare to hope we'd actually do it- the strength of some of the teams is just scary. This means that we now know our number for 2010 - number 10 - as only the top ten boats get a number for the following year.

So, now the work starts for next year, but we'll have a party around the boat when I get it shipped back (we packed it all up in the crate today), and acknowledge everyone's efforts when we all get back.

Cheers,
Peter



(Image courtesy of Scott Miller http://sjmpix.zenfolio.com)

Day three

For a day with less than a minute of boat running today was intense. Our boat is running well and we are slick at running it. We performed as predicted in the sprint race, losing some ground with a time in the middle of the field. We are happy, however, that it will not jeopardise our competitive ranking and we envisage a recovery with our strong event; the endurance race. Our commitment to assisting the Mexican team in their qualifying efforts came to a head this morning; after their near sinking yesterday they found their motor to be inoperable. Despite being the smallest team we split up for an ultimately unsuccessful attempt at repairing their systems. The boat was almost completely rewired by myself with help from representatives from Carnegie Mellon and Cederville universities; within 45 minutes. The proprietary brushless motor, being tied into the system's controller, prevented the necessary controller replacement from being possible; ultimately consigning the Mexican team to a retirement from the competition. In the meantime as well as running the battery charging strategy and preparing the boat for competition the rest of the team fine tuned the telemetry system to extend its range; not strictly necessary but a luxury to confirm the accuracy of our readings. Our lasting impression of the day remains the New Orleans boat which ran a 23 second 300m, its acceleration is literally explosive.

Richard, Team Tarka

Day two report

Another succesful day on the water gave us cause for encouragement. As we departed from the paddock area we were leading the event overall but with the top teams still to qualify we await further results with baited breath. Our major limiting factor currently is the boat's propellor, with such a low pitch we are unable to deliver the copious power that our electrical system is able to generate; causing us to lose a couple of seconds in the sprint racing over our rivals. Given the nature of the competition, however, we are confident this will not stop us from maintaining a high ranking. Our lead in the, all be it restricted, standings is in no small part thanks to our placing of 4th in the scoring for the technical reports. It was quite something watching some of the faster boats sprinting and I, for one, would love to have a greater emphasis on speed in the marking to encourage more high speed development. Given more support in the future we will be back with a competitive high speed configuration. Less fortunate were the Mexican team who employed our assistance in retrieving their sinking boat, which had been damaged in transit. We hope they will be able to patch the holes and qualify in time tomorrow. Good luck guys.

Richard, Team Tarka

Contest day one.

Today saw the start of the organised event and we pitched up with our towels earlier than everyone else, not because we're organised but because we're still waking up at 6am. We were subsequently moved on but were fortunate enough to be placed next to last year's winning team, from whom we intend to learn much. With a little fettling we passed the technical inspection, although we're still to find out whether they will allow our batteries as they are on the borderline of being too heavy. People seem to like our boat and the general consensus appears to be surprise at the speed with which we were able to construct it. Our work space accommodates us easily, especially when compared with the larger crews and they are all larger than ours. The boat spent the day standing proud, the most obvious boat from the entrance and looking smart with all its sponsorship decals, the union flag welcoming all interested parties. Interested parties were in plentiful supply throughout the day and I've become used to being introduced as 'Richard, the one you won't understand'. We left the boat this evening ready for our seaworthiness trials tomorrow morning and headed for a provided supper at the university football team's stadium. Some more calculations await our attention this evening, as does a pack of beer.

Richard, Team Tarka

First update from Arkansas

After spending yesterday fixing the multitude of broken boat parts we were able to commence testing today. The boat was run for approximately 4 hours in variations of the endurance configuration. A close to optimum configuration has been found and further analysis of data later tonight will allow us to select a number of parameters that are still unclear. The boat performed well and we are optimistic that it is competitive, in the endurance configuration; based on the information gleaned from local competitors. We are prepared to be shocked by the speeds that the faster boats may reach in the sprint configuration. Observations have shown that the local boat uses two motors, which are identical to our one; an extravagance we simply could not afford. The custom props are another significant difference that with extra funding and time next year we intend to consider. Despite our low cost solution local observers appeared to be impressed and we were pleasantly surprised at how much running we achieved; the sun here is good, for the boat at least. We are now off to sample the delights of the local brewery, wish us luck. Team Tarka

IEEE talk

Peter Wilson gave a talk hosted by the IEEE student branch this evening, on the progress of Team Tarka and the Solar Splash competition. We were also recruiting for a team for Solar Splash 2010. Please get in touch if you'd like to be involved next year.

Tarka shipped off today

Tarka was on display outside the Mountbatten building on campus this morning, in fantastic sunshine. Lots of ECS staff and students came to look and ask questions before we packed her up into the shipping crate, and onto a lorry to begin the long trip to the US.

See the ECS news story too.

Boat Launch

The boat launch was totally successful!

It was really great having people around to check the boat out, and I think the press really enjoyed it too! Check out the following links for the press coverage:

• http://www.ecs.soton.ac.uk/about/news/2457
• http://www.bsn.org.uk/view_all.php?id=15055
• http://www.dailyecho.co.uk/search/4301287.Solar_powered_speedboat_makes_a_splash/

Some of the videos are pretty funny! You can see me with the strange posture as I was trying to get my weight as far forward as possible to get the nose down.


After all the press had left, everyone had a go on the boat. It was quite exciting seeing everyone's different style of driving, as well as just how manoeuvrable the hull is.

First powered test on the water.

Tarka went out on the water this evening for her first powered test. With only two batteries and even those not fully charged, it was still very impressive to see the speed and manoeuvrability on the water. It's really very pleasing to see what we've achieved in such a short time, and a relief that we will have a good demonstration for our press launch tomorrow!

Solar panel testing

It was one of those rare bright Monday mornings where the intense sunlight was shining down on our south-facing Mountbatten roof garden. We decided to use this space as our solar panel test facility for the day.

The 215W SunPower panels were specifically chosen for their superior power to weight ratio and adequate efficiency. They were connected directly to a neat-looking MPPT, which was wired to a 12V Varta battery.

The selected MPPT has a set of indication LEDs that correspond to its charging status. Once the panel packaging was removed and the sunlight was exposed, the appropriate LEDs flashed on indicating that the panel was successfully charging the battery.

For the remainder of the morning we took some voltage and current readings in order to identify the charging characteristics of the power charging system. These measurements will be later used in optimising the electrical performance for the endurance race.

Boat construction full steam ahead Part II

Recently, signs of anxiety had dawned upon members of the team after learning that the deadline for shipping the boat was just under a month. This led to significant progress on the hull construction front.

Eagerly pressing on, the bulkheads were placed in their relative positions whilst piecing together the separate panels of plywood on top and adjoining them with cable ties.




As a result, we got our first full view of the boat profile; with its sheer size yet to sink in...



Unfortunately, while bending one of the front panels near the bow section we noticed a sudden crack forming, which clearly extended over 7 cm from the bottom edge.


At the time it seemed most sensible to repair the fracture by filling it with epoxy glue, just as we did along all the other panel edges.

A crucial part of the hull construction was adjusting its shape by positioning reinforcements along the edges. This was accomplished by carefully placing stringers over the sides of the boat and clamping them down until the glue dries. The stingers were added simultaneously with the aim of ensuring perfect symmetry along the axis of the boat.


Still, thing were running behind schedule and Dirk had asked for someone to takeover during his trip to Denmark. I thought this would be a good opportunity to offer a hand as I’ve always been keen on building a boat.

Armed with documents written earlier for each process step and the relevant data sheets I instantly got down to business. I also had Rich, Pedro and my brother come over and provide help with what was to be a fairly laborious, yet enjoyable, experience.

In a nutshell, our weekend consisted of the following:

Removing the cable ties

Sanding down the edges

Adding epoxy and glass fibre tape over all the seams of the boat

And laying a uni-directional glass sheet from bow to stern in order to reinforce the boat along its length.

Of course, that work only concerned the inside of the boat. Next, came the outside –the never ending story!

As with any racing boat the outer surface must be designed for ultimate smoothness. In our case, this was achieved by filling all the bottom panel edges and holes with epoxy, waiting for it to dry, sanding and then dusting off any excess. It is difficult to recall the number of times we repeated this process but we certainly went as far as to ensure that the hull wasn’t sanded away into one big pile of wood dust.

So here we are, sanding all the way through the night, removing any bumps or ridges in sight.

Rich spending most of his days resolving that crack:

Upon arrival, Dirk also got a piece of the action having bought a sanding disk for his drill, which he had previously opposed to using for the reason of dealing with extra thin plywood!

During Reuben’s visit we managed to get a look at his well crafted gearbox that was specifically designed to fit with our outboard and Lynch motor.

Here it is in action...



Obviously, for him, there was no escape from joining the sanding club...

The exterior of the boat progressively refined to a nice, smooth and regular surface. Eventually, after sustaining a few hand cuts and burses, a sore back and a permanent high from the smell of epoxy we finally reached a point where we felt confident in her curves!

It was time to bring her out into the fresh air, give her a very thin layer of epoxy and a good wash...

Once that was done we got out the grey paint and applied three coatings:

After the third coating we decided to prepare for our first launch in the water.

Lets hope this baby can float!!!

Scarphing the Scarfs

Scarfs, Scarphing is all very stressful and intense....

Never perfect, always difficult... not bad, but highly frustrating and very rewarding.... The kindof thing you pat yourself on the back for, but get frustrated with yourself for not having done better and faster.

Intense week! Things are really getting quite stressful! Our Monday meeting started with Reuben getting really stressed, with the scarfs not being completed. After Jess and I worked really hard trying to get them lined up,