Why is the Scoutship air raft open topped?

[far-trader]

More counterpoint speculative debate

Because it's a flying Jeep.
Go find why Jeeps are open-topped and you'll have your answer.

IF my recollection is correct...

One of the (biggest) reasons the jeep was roofless, and had a fold down windshield (and the pintle mount had to be easily and quickly demountable iirc), was due to being required that it fit in a certain dimension based on the Army transport needs (a small plane iirc*) at the time. It couldn't be taller than it was for that reason. You'll note the Jeep was replaced by Hummers, with roofs, and much more, partly (largely) because their (modern) transports are much more accommodating.

* I have an image in my memory of a newsreel scene of a GI driving a Jeep out the back of a plane, with the windshield down and having to lean way over in his seat (below steering wheel height) so he didn't knock his head on the way out.

The air-raft bay on the Type S is likewise NOT so constrained and there is really no good reason the air-raft shouldn't have a roof IF that is the logic applied

Perhaps you're thinking "Well sure, but back in the early days the predecessor of the Scout ship DID have a tiny half-height air-raft bay because that's all the room there was, and THAT is why the air-raft is open topped!" Which is ok. Except then you have to answer why the air-raft was never upgraded once the Type S had the room to spare. Or why some other use wasn't made of the gained tonnage.

EDIT: But essentially yes Icosahedron nailed it. The reason IS "because the air-raft is a flying jeep". Now, WHY the air-raft is a flying jeep is another question, with some good answers already provided. Because it's cool being my favorite.

 

[Whipsnade]

But, jeeps don't fly...

Sturn,

True, but complaining that the air/raft that replaces the jeep flies is like complaining that the jeep that replaces the mule doesn't walk, kick, or produce manure.

... especially into vacuum.

Oddly enough the jeeps the Apollo missions took to the Moon were used in vacuum.

Anyway, there are far more worlds with atmospheres in Traveller sysgen than there are vacuum worlds.

The real problem here is that OP and you are examining the issue in far too much detail. The air/raft is and was meant to be a somewhat capable, somewhat cheap, and somewhat fantastic method of transportation in a science fiction setting. Pointing out that the air/raft isn't enclosed or isn't pressure tight ignores the fact that the same document that introduced the air/raft also introduced two other grav vehicles that are enclosed and are pressure tight.

This is an apples and oranges situation. Complaining that an air/raft isn't like a g-carrier is like complaining that a banana doesn't taste like a strawberry.


Regards,
Bill

 

[Dragoner]

More counterpoint speculative debate



IF my recollection is correct...

One of the (biggest) reasons the jeep was roofless, and had a fold down windshield (and the pintle mount had to be easily and quickly demountable iirc), was due to being required that it fit in a certain dimension based on the Army transport needs (a small plane iirc*) at the time. It couldn't be taller than it was for that reason. You'll note the Jeep was replaced by Hummers, with roofs, and much more, partly (largely) because their (modern) transports are much more accommodating.

* I have an image in my memory of a newsreel scene of a GI driving a Jeep out the back of a plane, with the windshield down and having to lean way over in his seat (below steering wheel height) so he didn't knock his head on the way out.

The air-raft bay on the Type S is likewise NOT so constrained and there is really no good reason the air-raft shouldn't have a roof IF that is the logic applied

Perhaps you're thinking "Well sure, but back in the early days the predecessor of the Scout ship DID have a tiny half-height air-raft bay because that's all the room there was, and THAT is why the air-raft is open topped!" Which is ok. Except then you have to answer why the air-raft was never upgraded once the Type S had the room to spare. Or why some other use wasn't made of the gained tonnage.

EDIT: But essentially yes Icosahedron nailed it. The reason IS "because the air-raft is a flying jeep". Now, WHY the air-raft is a flying jeep is another question, with some good answers already provided. Because it's cool being my favorite.

IIRC, the main reason the Jeep was a rag top is because of the 1300lbs weight requirement. Which sounds totally logical with starships as well, because any weight you save in once place could be used in another.

 

[the angle]

I suspect that it may also have something to do with the fact that the air/rafts in the Dumarest of Terra stories were open-topped, and those stories had a big influence on Traveller. Besides, if it had a roof, it wouldn't be an air/raft. When's the last time you saw a raft with a roof? That would make it a houseboat.

Steve

 

[far-trader]

IIRC, the main reason the Jeep was a rag top is because of the 1300lbs weight requirement...

Could be, certainly part of it anyway.

Which sounds totally logical with starships as well, because any weight you save in once place could be used in another.

It should, but of course very few of the Traveller ship design rules concerned themselves with mass (weight) given gravitics. Mostly it was about volume, and the "4ton" air-raft as laid out could be fit into "2tons" IF it were stored half-height. But it isn't, which makes using it much easier but also means there's no good reason it shouldn't have had a hardtop from the start. No good technical reason anyway. There is the coolness factor and the rest of the meta-game reasons already mentioned which trumped in-game logic and sense. And nothing wrong with the choice made either imo.

 

[Dragoner]

Could be, certainly part of it anyway.



It should, but of course very few of the Traveller ship design rules concerned themselves with mass (weight) given gravitics. Mostly it was about volume, and the "4ton" air-raft as laid out could be fit into "2tons" IF it were stored half-height. But it isn't, which makes using it much easier but also means there's no good reason it shouldn't have had a hardtop from the start. No good technical reason anyway. There is the coolness factor and the rest of the meta-game reasons already mentioned which trumped in-game logic and sense. And nothing wrong with the choice made either imo.

Yes, I wasn't meaning to contradict your ealier statement, not what I was trying to say, the folding windsheild was also a big reason I bet. I do find the hand waving of weight requirements on starships a bit odd, but oh well. However the upside of that is that maybe there is a handy rack where you could stack two air/rafts. Sweet.

 

[far-trader]

Yes, I wasn't meaning to contradict your ealier statement, not what I was trying to say...

No worries I didn't take it wrong, just clarifying.

SIDEBAR:

I do find the hand waving of weight requirements on starships a bit odd, but oh well.

Agreed. I've long argued and fought (not terribly hard mind you ) that the original CT rules did not in fact refer to displacement tons but standard 1G mass tons. It always felt more science grounded and there are examples in the LBBs to support that the design rules were mass and not volume (chiefly the calculation of how many guns are in a "ton" of cargo). And (also another example for the argument) it would mean that the deckplans are not wrong since they show volume and not the associated (mass) tons. However I'm pretty sure Marc has stated definitively that it is not the case, that the design rules in CT always were displacement and not mass.

However the upside of that is that maybe there is a handy rack where you could stack two air/rafts. Sweet.

Indeed. A cool idea!

 

[Dragoner]

The 1G ton (mass) does make some more sense, at least scientifically, versus the DTon, 40 cubic feet (the displacement of a ship in water). Then how do you calculate how much a ship actually weighs when it lands? I know there is a formula somewhere, but that seems to way over-calculating the matter.

How much does the average Type S scout or Free Trader weigh in a normal gravity?

Oh yeah, there are some formulas, though it shouldn't be dTons, but Gross Tons.

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

Gross Tonnage (GT) is a function of the volume of all ship's enclosed spaces (from keel to funnel) measured to the outside of the hull framing. The numerical value for a ship's GT is always smaller than the numerical values for both her gross register tonnage and the GRT value expressed equivalently in cubic meters rather than cubic feet, for example: 0.5919 GT = 1 GRT = 2.83 m³; 200 GT = 274 GRT = 775 m³; 500 GT = 665 GRT = 1,883 m³; 3,000 GT = 3,776 GRT = 10,692 m³), though by how much depends on the vessel design (volume). There is a sliding scale factor. So GT is a kind of capacity-derived index that is used rank a ship for purposes of determining manning, safety and other statutory requirements and is expressed simply as GT, which is a unitless entity, even though its derivation is tied to the cubic meter unit of volumetric capacity.

Tonnage measurements are now governed by an IMO Convention (International Convention on Tonnage Measurement of Ships, 1969 (London-Rules)), which applies to all ships built after July 1982. In accordance with the Convention, the correct term to use now is GT, which is a function of the moulded volume of all enclosed spaces of the ship.

It is calculated by using the formula :GT= K*V , where V = total volume in m³ and K = a figure from 0.22 up to 0.32, depending on the ship’s size (calculated by : K= 0.2+0.02*log{10}*V ), so that, for a ship of 10,000 m³ total volume, the gross tonnage would be 0.28 x 10,000 = 2,800 GT. GT is consequently a measure of the overall size of the ship

 

[far-trader]

SIDEBAR:

For what it's worth and those interested...

In the comparison with and discussion about the Jeep, I found the pertinent original 1940 Army requirements:

"Height not to exceed 36 inches (increased to 40 inches 1 July)"

...but no mention of exactly why. I'm still sure it had to do with transporting them. There's also mention in the requirements of it having a "rectangular body and folding windshield" (with dimensions and for the same transport reasons I expect) and of course the weight requirements, though those seemed less set in stone:

"Weight not to exceed 1200 pounds (increased to 1275 lbs 1 July and then to 1308 lbs)"

I seem to recall something about pressure on the Army to loosen many of the requirements as those involved in production were finding it difficult to meet all the requirements.

 

[Icosahedron]

If, like the Jeep, air rafts were used as military vehicles, they could follow the logic of the Jeep in that if they're only a metre high, you can store them three high in a standard cargo bay and get more into battle for a given number of transports - since dT is a measure of volume rather than mass...

 

[the angle]

If, like the Jeep, air rafts were used as military vehicles, they could follow the logic of the Jeep in that if they're only a metre high, you can store them three high in a standard cargo bay and get more into battle for a given number of transports - since dT is a measure of volume rather than mass...

I suspect that this is spot on as far as the jeep's size requirement, and it probably came about because of the dimensions of the cargo hold on a liberty ship. Getting vehicles across the Atlantic in the most efficient manner was a major concern. Likewise, many British tanks were uncommonly narrow because the trains which transported them from the industrial north to the southern ports had to pass through narrow tunnels. These types of factors lie behind many seemingly odd design mandates.

Steve

 

[Andrew Boulton]

Likewise the (West) German rail network limited the size of NATO tanks.

 

[Imperial Planetologist]

Reason - so it would look like the air/raft thing Luke Skywalker drives in Star Wars.

More likely the sky-rafts from Planet of Adventure.

 

[BlackBat242]

Many of the "flitters" of Andre Norton's sci-fi (from the 1950s on) were open-topped (at least a couple of stories have someone firing at airborne beings above the flitter with hand-held weapons with no mention of hanging out of windows)... and they flew, although she never described the exact means of propulsion (air-cushion, lift-fan, anti-grav... we don't know).

They also tended to be limited to 4 persons, with two more crammed into the cargo area in emergencies.

 

[Mithras]

AE Vogt's 'War Against the Rull' (1959) begins with our hero Jamison (yes !) having a desperate fight with a 6 armed alien while hanging from a sky raft open-topped grav vehicle.

 

[mbrinkhues]

Likewise the (West) German rail network limited the size of NATO tanks.

Actually the load gauge of ALL western european railroads limit tank width. That's because in 1912 they agreed on a standard gauge (Berne gauge), The one big exception are the Britisch with a smaller gauge. Not that US gauges are much bigger. Certainly not so much as to affect tank building (Tank maneuverability is among others length/width based)

And that you can fit oversized mobile bunkers on a normal sized train was shown with the two "SS Panzerviagra" tanks of the Nazis the Tigers.

 

[Andrew Boulton]

The German network was particularly important because that's where we expected to fight!

 

[Samules]

RIDIN IN MY PIIIIIINK AIR-RAFT, PIIIIIINK AIR/RAAFT!

:rofl: I'm sorry it had to be done.



The lack of roof is purely stylistic in my view. Use as a troop transport makes no sense because a G-Carrier is half as heavy and expensive as its transport equal in air/rafts and has a turret to boot!

 

[mbrinkhues]

The German network was particularly important because that's where we expected to fight!

And the one place where rail movement was a peacetime only job. Nothing says "don't use the Bundesbahn" as well as a pair of SU-25 straffing your train. Well okay, the Bundesbahn service, ability to hold schedules, bad maintenance, low readiness state in winter/autum/fall,... is actually a lot more dangerous. But the Frogfoots are more fun to watch

 

[Sanjuro]

The load gauge of railways has determined a lot of things.
The limiting factor in the size of the Space Shuttle is the size of the Solid Rocket Boosters. The size of the SRBs is limited by the diameter of US railway tunnels, as these are the largest components carried by train. The diameter of the tunnels is related to the gauge of the tracks- 4 feet 8.5 inches.
The US railway gauge is 4ft 8.5in because the engineers who built the first US railways were British, and had previously built railways in Britain.
The British rail gauge was 4ft 8.5in, because the earlier horse-drawn railways had a gauge of 4ft 8.5 inches- which in turn was because the standard gauge in carts in Britain was 4ft 8.5in, back to Roman times- because that was how far apart the ruts in the road were.
This was because the Roman army defined a standard gauge for chariots (4ft 8.5in) based on the width of the rump of a standard horse.
So the next time you look at some piece of equipment, and wonder which horse's a*** drew up that specification, you may very well be right!