Masalai,
Have copied just a few of the relevant posts.
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Posted: Wed Feb 27, 2008 12:13 pm
As a result of research about diesel electric propulsion for a cruising catamaran I am planning to build, I collected considerable information. A marine environment is tough, so it's possible that some marine equipment could be used to fabricate a powerful diesel electric locomotive within the loading gauge of the two railways. The OSSA 200 Kw generators are very compact.
Here are some sites worth bring to the attention of the engineers.
http://www.ossapowerlite.com/products/motors/motors.htm
http://www.ossapowerlite.com/products/generators/generators.htm
http://www.asmomarine.com/2005/asmo_uk/04.shtml#Q01_12
http://www.solomontechnologies.com/
http://www.fischerpanda.co.uk/electric_propulsion.html
Perry
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Posted: Thu Feb 28, 2008 1:05 pm
Hello Tony,
It depends on what you mean by expensive and heavy. The 1200 Ah batteries specified for my 60' catamaran are for traction and full house services. These batteries and the twin electric propulsion motors weigh less and cost less than two 60 HP propulsion diesels, one diesel 6 Kw generator, diesel fuel tanks and the relevant number of house batteries, which presently go into a conventional system for equipping a cruising catamaran. Diesels are also difficult and expensive to service in boats. Ask any marine engineer. The installation cost for my system is considerably lower, as well as much easier. Even the cooker is electric.
The two ASMO 17 Kw electric motors I shall use for propulsion whilst manoeuvring each weigh only 40 Kgs and when sailing at 6 knots+ they will rapidly recharge the batteries. She will cruise at 20 knots under sail.
http://www.asmomarine.com/2005/asmo_uk/pdfs/Asmo_Marine_THOOSA_17000.pdf
Thus I can dispense with any dangers and costs for cooking with LPG and all costs associated with diesel propulsion. The sum of the whole is greater than the parts. Granted my solution is only applicable because of the recent developments in the equipment and the catamaran. Prior to 2003, cruising catamarans weren't swift enough. See Gunboat 62.
http://uncutvideo.aol.com/videos/cabce7fe77982ed5cbb7fcdf0dd91825
Either a DE loco or a battery loco. The only real difference being the batteries or the diesel generator. The downhill stretches can be used regeneratively with the battery locomotive. There is a good case for it.
My catamaran represents a logical development in view of rising fuel costs and even with the cost of replacement batteries in 10 years time, the convenience of an all electric vessel plus the smaller running cost per nautical mile fully justify my choices. Alternative traction on the two railways might just benefit from a less traditional approach.
Regards,
Perry
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Posted: Thu Feb 28, 2008 11:17 pm
Dear Tony,
It's either diesel electric or battery, but not both. The batteries needed for a 1000 HP narrow gauge locomotive are far fewer than for a standard gauge locomotive. Then again, would the two railways require such power, as 25 mph is the line speed? A Bo-Bo battery powered locomotive would have high tractive effort and if it were necessary to haul the batteries in a separate wagon, then the possibility exists to have extra capacity on charge for more intensive services.
These are just ideas triggered by designing my catamaran to be independent of diesel fuel. For me, it's the logical step. A 17 Kw Thoosa electric motor has the torque to replace a 60 HP marine diesel. Two will power a 13 tonne catamaran to 10 knots!
PS
Have just received an update from a boat builder who is developing a DE sailing catamaran.
http://www.africancats.com/
Regards,
Perry
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From peterk. Posted: Fri Feb 29, 2008 3:54 am
Perry wrote:
"Tony,
It's either diesel electric or battery, but not both. The batteries needed for a 1000 HP narrow gauge locomotive are far fewer than for a standard gauge locomotive. Then again, would the two railways require such power, as 25 mph is the line speed?
The figure of 1000hp came from some speculative conjecture on here (see earlier in this thread) related to pulling a 12 coach train plus failed NGG16 up a 1:40 hill at 25mph. Something of an unrealistic corner case really, but fun to conjure with in an idle moment. In the real world, the power requirement could be lowered by accepting a slower speed in that "rescue" scenario. Trains probably wont load to 12 coaches either.
Whilst not being privy to any of the real management's thinking I seem to recall a hint (was it from Mike Hart??) that something in the 600hp region would do the job.
Perry wrote:
A Bo-Bo battery powered locomotive would have high tractive effort
Yes any loco can be arranged to have a high tractive effort - but it is power that governs its ability to exert that tractive effort at a useful speed. Taking the energy density figure for the Lithium batteries from the link posted above ie 90W-h per kg a 750kWh battery pack would weigh in at 8.3 tonnes - handy to have on board the loco for adhesion purposes I would think. Of course such a loco would only have sufficient endurance to exert its maximum (power) effort of 750kw = 1000hp continuously for an hour or so, but since the WHR is more or less a hill you go up one side and down the other, this is probably another too-extreme corner case. I guess the loco would only need to give flat-out maximum power for at most half the time, and for large parts of the downhill bits it can be recovering energy through regenerative braking. Thus a 2 hr trip end to end of the line including getting out of the way afterwards to plug itself in, with some 600-1000hp performances going up the Pass seems within the realms of possibility from a single charge.
Perry wrote:
A 17 Kw Thoosa electric motor has the torque to replace a 60 HP marine diesel. Two will power a 13 tonne catamaran to 10 knots!
hmm... choice of winding design can mean the stall and low speed torque of an electric motor is greater than the diesel, but sorry, torque at a given rpm = power, and 17kw is less than half of 60hp (= 44 kw in new money) so it all depends on the rev range you want to use. There will be a speed above which that 60hp diesel can spin harder and faster than the electric motor. At lower speeds the diesel's power simply isnt being used fully. - Of course also in a boat it depends on the propellor's ability to use the power at the rpm concerned, choice of motor speed/torque curve and propellor go hand in hand, and whats right for the diesel wouldnt be right for the electric motor and vice versa, but I digress...
I guess the point is that batteries have come a long way since the 50's and 60's technology studies mentioned above, but they still have a way to go, otherwise the US army would not be earmarking $15M for a one-off shunter, they'd be slinging them together from well tried components for a tenth of the price - rather like the diesel loco builders could do for us if we had the $1.5M, which we dont!.
Ho hum. fun to ponder on all the same.
PeterK
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Posted: Fri Feb 29, 2008 7:47 am
Hello Peterk,
"There will be a speed above which that 60hp diesel can spin harder and faster than the electric motor. At lower speeds the diesel's power simply is'nt being used fully. - Of course also in a boat it depends on the propeller's ability to use the power at the rpm concerned, choice of motor speed/torque curve and propeller go hand in hand, and whats right for the diesel wouldn't be right for the electric motor and vice versa, but I digress... "
Absolutely correct. The electric motor will turn a larger propeller with a coarser pitch at lower revs without slippage and this delivers higher efficiency. Some marine diesels rev to 4400 and so need a 2-1 gearbox with the propeller sized to suit. Towards the 10 knot top speed the smaller propeller begins to loose "grip" on the water. There are a number of companies working on DE boats as the disconnection offered by the DE principle frees up more internal space for use as accommodation.
I am convinced a battery locomotive could be built at Boston Lodge from scratch, frames, bogies, the lot, for much less than £1.5 million. How about the Swiss Crocodile outline, without working pantographs?
http://www.railfaneurope.net/pix/ch/SBB_CFF_FFS/electric/historic/crocodile/14270.jpg
http://en.wikipedia.org/wiki/Image:Ce6-8.jpeg
http://en.wikipedia.org/wiki/Image:Ge_6-6_I_407_Krokodil.jpeg
http://86242.fotopic.net/p31914663.html
http://86242.fotopic.net/p31997064.html
Then there is this.
http://www.spikesys.com/GG1/
http://www.spikesys.com/GG1/paint.html
This would be weird.
http://www.dself.dsl.pipex.com/MUSEUM/LOCOLOCO/leader/leader.htm
Regards,
Perry
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Posted: Thu Mar 06, 2008 9:17 am
"Then there's the drive format - C-C has all three axles in the bogie driven as a single unit from a single point (simple, single Cardan shaft from the traction drive to the bogie and simple gearboxes on each wheelset) against Co-Co where each axle is driven independently of the others (lots of small drive systems, but superb control during start and slippery conditions)."
Bob has summarised very well, which is why I think the Crocodile system using connecting rods and a single Cardan shaft is a good solution, familiar to steam railway engineers, especially at Boston Lodge.
http://www.railfaneurope.net/pix/ch/SBB_CFF_FFS/electric/historic/crocodile/14270.jpg
Returning to the subject of battery power for a moment, here is a link to a very useful article by Nigel Calder who is a bit of a buff when it comes to latest technology. Go to page 104 at
http://www.proboat-digital.com/proboat/20080203/
Some who post here may have heard of Odyssey batteries, but I hadn't, so the information has enabled me to improve the design of my catamaran. However, that's another forum.
C'mon chaps, a Crocodile (battery powered) chasing a Garratt up and down Snowdonia (Kilimanjaro). That's really African!
Regards,
Perry
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Posted: Thu Mar 06, 2008 1:15 pm
An Internet search revealed these two sites.
http://www.active-robots.com/products/power-supplies/odyssey-batteries/battery-guide.pdf
http://www.active-batteries.co.uk/enersys-odyssey-batteries-c-104.html
With a recharge rate 15 times faster than AGM batteries, a battery powered Crocodile could be recharged for a return run in less than an hour. The capital cost for the batteries is comparable with a diesel powered generator, without the complexity and a battery powered locomotive would cost less to run than a diesel electric.
DC motors:
http://www.menzel-elektromotoren.com/en/gleichstrommotoren_lagernd.php
http://www.railway-technical.com/tract-01.shtml
http://www.beta-power.co.uk/Motors.html
OK, I can understand there will be some reservations about having a battery powered locomotive that could drag the entire rolling stock of both railways combined as one train, up and over the route, but what a hoot!
Perry
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From Tony Smedley
Posted: Thu Mar 06, 2008 2:50 pm
Perry,
Although having a gut feeling that it doesn't sound right, I am intrigued by your ideas for a bettery loco. Not having the inclination to do the necessary homework myself, can I ask whether you can suggest figures for battery capacity requiired, its weight and space requirements, its cost including suitable charger and the voltage suggested.
In theory. a DC constant voltage power supply requires relatively simple motor controls, but they would need to be efficient, without energy wasting resistors,
Tony
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These extracts are part of further discussions, as wide ranging about railway propulsion as you will find opinions about propelling boats. I wonder if I can persuade the Directors to undertake a trial with sails along the flat section from Porthmadog to the foot of Nantmor Incline?
Regards,
Perry