Naval ships landing gear

[maitrejeanth]

Hi there, it's been a long time....
According to CT, streamlined ships of up to more or less 1Kt displacement are able to land on planetary surfaces.
ADV 1 refers to the "massive landing gear" of the Kinunir-class ships.
Would this landing-gear be aircraft-style wheels or just plain skids ?

 

[kafka47]

Canon has pictured starships with wheels and without wheels. But, in the era of Antigrav, I would have thought wheels to be redundant.

But maybe on some starships, it is a backup system allow a streamlined ship to glide and land like the shuttle. Remember, Navy ships are there to ferry troops quickly from A to B. Therefore, they would be relative void of extras (eg. portholes are replaced with viewscreens). To create a starship runway would take too much time. So, I could see HeLPaR rockets as well as antigrav to "clear" a landing space.

 

[vutpakdi]

Originally posted by kafka47:
Canon has pictured starships with wheels and without wheels. But, in the era of Antigrav, I would have thought wheels to be redundant.

Wheels would allow ships to be moved on the ground more easily if they didn't have power.

I would imagine that ships have skids with wheels in them. The skid portions are the primary support and allow for landing in rough terrain. The wheels allow the ship to taxi and be moved by ground equipment if necessary.

Ron

 

[Andrew Boulton]

I'd say skids in most cases. The wheels would have to be enormously tough to handle the weight of all but the smallest ships.

 

[Straybow]

With grav tech even the streamlined ships would have landing feet rather than wheels. It is far safer to "brake" to a stop hundreds of m above the ground surface, maneuvering to a parking area, then land vertically. 100-200 dT ships might have wheels for convenience in low infrastructure ports.

 

[vegascat]

Once I park a ship, I want it to stay put! A starport with repair capability would have lift capability to move a ship needing repair, other than that, the ship will stay parked. To move a ship on the ground would be dangerous, requiring preparation and coordination.

 

[Straybow]

True, an S-class would probably weigh as much as a 747.

 

[Spiderfish]

I imagine the really large vessels would have massive "feetlike"landing gear something like the Nostromo in Alien.

 

[Spiderfish]

I imagine the really large vessels would have massive "feetlike"landing gear something like the Nostromo in Alien.

 

[aramis]

IMTU, certain classes have skids, certain ones have feet, and a rare few have rollers on the skid bottoms (ala the old BSG vipers).

Type S, A, A2: skids
S2, R: Tires, on gears much like 747's & C5A's...
T: tires or roller-skids, more often the latter.
MercCruser: None (reinforced cowlings on the engine pods)

 

[Straybow]

You really want some kind of strut and pad system for any ship that is designed to land. Load transfer is critical. A bad landing or subsidence under the ship at an unprepared landing site (even a class E) can really screw with the hull SI. Struts can take the damage in such situations; they're somewhat expendable.

 

[marginaleye]

Most habitable planets have at least a moderate amount of open water.

Why not just design starships to land in water, and float like boats?

Starships are already air-tight, and their weight wouldn't all be concentrated on a few points. There would be no need to pave or maintain a smooth surface. Any pond or big ditch would do.

 

[marginaleye]

Most habitable planets have at least a moderate amount of open water.

Why not just design starships to land in water, and float like boats?

Starships are already air-tight, and their weight wouldn't all be concentrated on a few points. There would be no need to pave or maintain a smooth surface. Any pond or big ditch would do.

 

[Slink182]

Although water landings may sound like a good idea, and though star and space ships are air-tight, to float a such a ship would require that they follow the standard bouyancy displacement rules.

That is, to float 1 ton of ship, you have to displace 1 ton of water (or whatever liquid is predominant on the planet). There's also the issue of stability of the floating ship (i.e., keeping it right-side-up). A lot of the ship designs (with the exception of most of the small crafts) would have a problem with stability, likely leading to the ship listing, and that's just from the existing design.

Factor in cargos that are rarely uniformly distributed across the hold, unusual ship profiles, and that most passengers would not be impressed having to be ferried ashore, I can see most decent starports would have hard landing surfaces.

As for wheels, well, a "light" 747 jumbo jet weighs empty and dry 377,000 lbs (171 tonnes). The "heaviest" 747, fully loaded with passengers and fuel, weighs about 921,000 lbs (~418 tonnes). Granted, they have to wheel around on reinforced concrete runways, but wheel/hydraulic tech existed to support these jets during the '60s, '70s, '80s and '90s. Imagine what the tech would be like down the road.

IMTU, all ships that are streamlined and were built at a TL capable of supporting a-grav only have big landing foot plates. If they need to be taxied around the field, the ships are powered up so they become gravity neutral, and the utility vehicles pull it to wherever it's suppose to go. TLs under that, they have wheels (sometimes LOTS of wheels) and landing plates.

 

[savage]

wheels?

Traveller canon has gravitics...thrusters...ideal star travel.
All they really require is hydraulic landing feet.


Savage

 

[alanb]

I agree with the landing feet arguments.

The only potential problem occurs if a ship that doesn't have power has to be moved.

There are two solutions to this problem.

First, don't move it! Starports don't need runways. Landing bays can function as both launch pads and maintenance facilities.

Second, slip a grav-powered framework around it, switch it on, and carry on as if it had power. This is a big, expensive piece of equipment, but a largish starport can reasonably expect to have something of the sort.

Third, don't land... I suspect only the smallest vessels will land under all but the most extreme circumstances. Most vessels will "park" in orbit, or dock with a high-port and interact with the surface through small craft. Of course, not all of those small craft are necessary all that small!

 

[savage]

Good points alanb.

IMTU the highend starports have grav lifters. Tugs assigned to assist damaged ships in landing on the planet for extended stays...etc. Actually, I'd consider it to be the law.
Although, the not landing is a fine alternative.

Savage

 

[aramis]

Certain designs should be capable of MD-off landings. Some are implied to have this in their writeups (Serpent, for one).

And since the mass of a serpent runs to about 800 tons... it's about the fully laden weight of a C5A Galaxy... and somewhat smaller. So, for such a ship, I see no reason to NOT have the "Emergency landing capability" the airframe allows for... at the expense of needing a long, ard surfaced runway.

And really, the limits on landing gears are NOT the hydraulics... but the need for tires and brakes... and the tires to have enogh contact patch to not mire, and be resilient enough to sustain the touch-stresses and heat, while still stiff enough to support the mass. I suspect tire technology will improve through at least TL 13... by TL 14, in most dev trees, tires should be auxilliary/emergency equipment by then....

And roller-skids would be for REALLY smooth surfaaces... like landing bays.

Also, please remember, in certain editions, you don't get neutral bouyancy, you get around 0.1% weight remaining, but with full inertial mass; so thusly TNE craft really should have a much higher rate of wheeled landing gears than CT/MT/T20. Not conversant enough with GV to talk adequately about the GT Gravitics. Don't recall for sure if T4 used TNE style CG.

 

[alanb]

Whatever...

What makes your scenarios good is good.

I'm still a bit of a starport controller, when you get down to it...

 

[Commander Drax]

For the most part I think skids, or landing claws would be the most common, as they allow frontier landings (i.e a flat space). I recently designed a heplar powered airframed small craft that didn't have Contragrav lifters, and in the craft discription listed that it had wheels,on the grounds that it was a simple port to orbit shuttle, and wheels were the most logical way of satisfying its design criteria.... for any vessel over 300 tonnes in mass I would suggest they use skids, claws etc simply because of the weight involved, or even some retractable tracks (like a tank or the vehicle used to ferry the Apollo rockets from the hanger to the launch pad), though these would still use power. As per a previously posted reply (by someone else), I would suggest that grav assisted ships, either set down or hovver at low altitudes to move around if needed. If the ship is unpowered than I would think that any starport class c or above would have grav assisted lifting gear to move it or employ a tug to physically lift it off the ground and take it to a new location.