Future air transport

RogueMale · Post by **RogueMale** » 01 Jul 2010, 23:50

I thought it was well-known that the reason airships are no longer around is their past safety record:

http://en.wikipedia.org/wiki/Zeppelin

http://en.wikipedia.org/wiki/R31_%28airship%29

http://en.wikipedia.org/wiki/R33

http://en.wikipedia.org/wiki/R36_%28airship%29

http://en.wikipedia.org/wiki/R38_%28ZR-2%29

http://en.wikipedia.org/wiki/Airship_R101

This is not just because they were filled with hydrogen, and in any case there are problems with helium: it's rare and it leaks. If a way could be found to guarantee airships are as safe as aeroplanes, they could make a comeback and I'd like to see them again, but I'm unconvinced.

George Monbiot likes them:
http://www.monbiot.com/archives/2008/05 ... ing-light/.

stumuzz · Post by **stumuzz** » 02 Jul 2010, 09:21

We are not comparing hot air balloons with planes. The comparison I think is with one hot air balloon carrying 1400m3 of low density cargo ( crisps for example) and 20 HGV’s and one very large cargo ship carrying 1400m3 of crisps.

The fuel saving must be enormous. Especially when you take into account embodied energy requirements of ships, hgvs, roads, ports etc.

RogueMale · Post by **RogueMale** » 03 Jul 2010, 23:51

stumuzz wrote:We are not comparing hot air balloons with planes. The comparison I think is with one hot air balloon carrying 1400m3 of low density cargo ( crisps for example) and 20 HGV’s and one very large cargo ship carrying 1400m3 of crisps.

The fuel saving must be enormous. Especially when you take into account embodied energy requirements of ships, hgvs, roads, ports etc.

I don't doubt that the fuel saving would be enormous. I'm pointing out why we don't have them: we had them in the past and it was concluded they were unsafe. I would support their use, provided the safety problems can be overcome.

Lord Beria3 · Post by **Lord Beria3** » 12 Aug 2010, 16:31

http://www.worldskycat.com/images/SkyCat.pdf

See above on potential flying baloons.

JohnB · Post by **JohnB** » 12 Aug 2010, 17:21

Lord Beria3 wrote:http://www.worldskycat.com/images/SkyCat.pdf

See above on potential flying baloons.

The designer must have been a Gerry Anderson fan

Post by **adam2** » 20 Mar 2016, 09:44

Interesting development re airships here.
http://www.bbc.co.uk/news/uk-england-be ... s-35836218

I can foresee a number of uses for such craft including disaster relief, deliveries to remote places, tourism and sightseeing.

I can not foresee any large scale use of this technology though on account of the high cost and limited availability of the helium with which they are filled.

Even the manufacturers are only speaking of building about a dozen over some years.

emordnilap · Post by **emordnilap** » 27 Sep 2017, 12:47

Electric aircraft?

EasyJet could operate flights using electric aircraft within the next 10 years, according to a manufacturer with which it is collaborating.

Short-haul routes such as London to Paris or Edinburgh to Bristol could be flown using the battery-powered planes.

Feasible?

Post by **adam2** » 27 Sep 2017, 16:27

Yes, battery powered aircraft are a distinct possibility, a small one has already flown.
Even the best battery has an energy density lower than jet fuel so a long range seems unlikely, but for short haul, very likely IMHO.

It might even be possible to use a long trailing lead to power the take off in order that flight commences with 100% full battery.

Zero pollution at the point of use, and much reduced pollution in total if the electricity was largely from renewables.
Far less noise pollution, and probably safer.

emordnilap · Post by **emordnilap** » 27 Sep 2017, 16:34

adam2 wrote:It might even be possible to use a long trailing lead to power the take off in order that flight commences with 100% full battery.

What about take-off from a powered track? One idea. Power is switched off the track between take-offs.

Post by **kenneal - lagger** » 27 Sep 2017, 16:43

The greatest use of power for aircraft is the take off. If the take off was assisted, as in carrier based aircraft, the power storage requirement for any one flight would be greatly reduced. Gliders can be winched into the air so why not aircraft?. The winch might have to be a bit larger though.

Post by **kenneal - lagger** » 27 Sep 2017, 16:50

I didn't see the last two posts so sorry for the overlap.

The use of battery powered tugs on the ground for taxiing would save a lot of energy as well. Smaller airports so that aircraft don't have to travel for miles to get to the run way would help as well. Schipol for instance, has some runways a couple of miles from the terminals and the new Heathrow runway would be similar.

Post by **adam2** » 27 Sep 2017, 17:27

kenneal - lagger wrote:The greatest use of power for aircraft is the take off. If the take off was assisted, as in carrier based aircraft, the power storage requirement for any one flight would be greatly reduced. Gliders can be winched into the air so why not aircraft?. The winch might have to be a bit larger though.

Gliders are usually towed aloft behind another (fuel burning aircraft), not winched from the ground. Cant see towing working at a busy air port.

An electrified track might be a possibility, but would probably prevent use by non electric aircraft.
A trailing lead might be simpler. As an example consider a take off run of 500m. Install a fixed power supply at the mid point beside the runway. Use a 300m trailing lead, jettisoned automatically when the air craft is 250m past the supply point.
Attach the lead to the aircraft by use of powerful magnets so that it may pull free if not automatically jettisoned.

The cable could be relatively light in weight since it is used but briefly and no one would be allowed to handle it whilst live.
16mm PTFE insulated copper should be good for several hundred amps at several thousand volts.

woodburner · Post by **woodburner** » 27 Sep 2017, 22:12

Gliders are frequently and very often winched from the ground. Go to any significant gliding site to observe. The cost of aerotows is for the well-off glider pilots. The poorer ones use the winch. I have had launches of over 2000 feet from a winch launch, and 2700 feet from a truck towed launch. The only reason we couldn't get higher was the airway above the site.

Post by **adam2** » 28 Sep 2017, 08:17

woodburner wrote:Gliders are frequently and very often winched from the ground. Go to any significant gliding site to observe. The cost of aerotows is for the well-off glider pilots. The poorer ones use the winch. I have had launches of over 2000 feet from a winch launch, and 2700 feet from a truck towed launch. The only reason we couldn't get higher was the airway above the site.

Interesting, was not aware of this.
That makes electric aircraft more viable. The winch could be electric, and whilst the trucks used at present are probably diesel powered, an electric vehicle could be used.

Post by **kenneal - lagger** » 28 Sep 2017, 09:41

Thanks, Woody.

I was thinking a winch might be more comfortable for the passengers than a steam ram!