TOS Turbolift

[Christopher]

One thing I've sometimes wondered is, where exactly does the "turbo-" part come in? The prefix literally means "incorporating a turbine," but what role does a turbine play in the lifts' operation? Is it supposed to be like those old pneumatic-tube message systems driven by air pressure? Are the individual lifts themselves powered by turbofans or something similar? Or was it just one of those sci-fi uses of "turbo-" as a generic prefix for "advanced and futuristic" without any regard for its literal meaning, like Star Wars' absurd coinage of "turbolaser"?

As with so many things, The Making of Star Trek provided the answer. From p. 193: "The turbo-elevators operate in a way similar to huge pneumatic tubes, each elevator independently turbine-driven, controlled by computer-activated relays in the shaft that control and direct the air pressure created by the turbines." So both my first two guesses were right. It is a pneumatic system, but the individual capsules provide their own pressure/thrust, as I suppose they'd have to in order to accelerate or decelerate as needed.

This means it would be important to keep the doors sealed unless there were a lift car behind them, otherwise you'd lose pressure in the shaft and a lift above you might fall down.

Except, wait a minute, if the cars are propelled by turbines, which are presumably on the bottom and/or the top, how do they move sideways?

 

[Laura Cynthia Chambers]

Perhaps they sit in a slotted track that runs around the outside of the lift. They then move and lock into place on whichever side necessary.

 

[Just a Bill]

In reality, it's not very plausible for the turbolift system to have a pneumatic-tube basis. The shafts are a network with branches, the cabs move along more than one axis, and cab-swapping at terminals has to be extremely quick, based on what we see on the show. Pneumatics requires a tight seal between the cab and the walls, including at intersections, and requires each cab to travel along its long axis, like the capsules at a bank drive-up. I'm sure it sounded like a nice metaphor to whoever wrote that stuff for TMoST, but you can't "blow" cabs around a branching network along multiple axes, especially if the cabs aren't spheres.

Pneumatics rely on air pressure, and even if that pressure is generated by the cab itself, you still have to have basically exclusive use of the shaft while traveling. Otherwise the air pressure in cab 1 is using to go to the bridge is working directly against cab 2 which is trying to follow it, for example. This implies the need for a massive number of valves that open and close quicker than a human eyeblink. Furthermore, building the locomotion equipment into every individual cab is also very inefficient, and makes the cabs pretty huge, too. The turboshaft network is already a challenge to make fit in any kind of blueprint layout, and adding the need for pneumatic valves at every terminal and every junction probably makes it an impossibility.

But maybe the biggest obstacle to making pneumatics work is the need for cabs to be able to pass each other. Imagine a superhighway that can switch between two directions, but only allows cars to flow in one direction at a time. The delays would be very bad, like when a flagger at a construction site is holding up you and 20 other cars so 30 cars in the other lane can come down your lane. A multilane highway is much more space-efficient than multiple single roads, just as a single large shaft that allows two or three cabs abreast would be much more space-efficient than two or three parallel tubes going to all the same places in the x, y, and z axes. This of course is completely incompatible with a pneumatic system.

Probably the practical solution would be a rail system using a physical connection between walls and cabs. Cheaper, safer, faster, more space-efficient, and easier to control from a single computer. But I could be wrong. If somebody can show how pneumatics solves the problems and provides the rapid entry/exit behavior we see on the show, I would love to see it. I wish it could be pneumatic. I just don't see how it's possible.

 

[Christopher]

In reality, it's not very plausible for the turbolift system to have a pneumatic-tube basis. [etc]

Excellent points. If that's the case, though, what could the "turbo-" part mean instead? Maybe some kind of electromagnetic turbine powering a magnetic drive system?

But maybe the biggest obstacle to making pneumatics work is the need for cabs to be able to pass each other.

I've never seen any indication that they're capable of doing that, except by shunting off to a side track. All the depictions I've seen, aside from Discovery's ludicrous hammerspace roller coaster, presume shafts that are one car wide, with the motions and speeds of different cars computer-controlled to keep them out of each other's way.

 

[Laura Cynthia Chambers]

One of the scenes in the 2013 alt-reality Gorn game has Kirk and Spock maneuvering through the shafts - every now and then having to duck to the side to avoid being run over.

 

[Just a Bill]

Excellent points. If that's the case, though, what could the "turbo-" part mean instead? Maybe some kind of electromagnetic turbine powering a magnetic drive system?

I think you hit on the answer right here:

Or was it just one of those sci-fi uses of "turbo-" as a generic prefix for "advanced and futuristic"

It does seem like "turbo" has just come to mean "fast" in a lot of contexts.

I've never seen any indication that they're capable of [passing each other], except by shunting off to a side track. All the depictions I've seen, aside from Discovery's ludicrous hammerspace roller coaster, presume shafts that are one car wide, with the motions and speeds of different cars computer-controlled to keep them out of each other's way.

I doubt it has ever been depicted, but I've put a lot of thought into this over the past few years and I keep coming to the conclusion that the idea of single-lane shafts (like we see in the move diagrams) just wouldn't be sufficient. I'm not saying that every shaft everywhere is "multi-lane," but there would be some key areas, such as in the dorsal connector and in the main shaft leading straight up to the bridge, where it would be essential to avoid significant choke-points, especially in emergencies. Imagine a call to battle stations in the middle of the night shift, when suddenly a couple hundred crew members all need to get somewhere RIGHT NOW. If we can't have two or three lanes of cabs going through those key arteries, and in both directions, then it's gonna be a long wait before all stations report ready.

Now, maybe this means two or three separate shafts right next to each other, with transfer points between them (slowing things down again), but from the standpoint of efficiency the thing that I always come back to as making the most engineering sense is a shaft that can grip a cab from any of its walls and allows at least two cabs to pass each other.

And finally, as much as it pains me to invoke the very worst of the classic-crew feature films, this scene does suggest a large, arterial shaft whose distorted hexagonal cross-section is perhaps best explained by having capacity for three cabs abreast:

But this last bit is certainly not the hill I want to die on. That movie was crap.

 

[Christopher]

As I understand it (from conversation with knowledgeable people back on the Gene Roddenberry's Andromeda discussion boards), real naval crews don't generally use elevators to get around, since they can easily get stuck if a shaft is damaged in combat, and since naval personnel are expected to be in good enough shape to get around on foot. But for Trek, it was far more practical to build a small elevator set than to build stairways between levels or whatever (though they did have ladderways in the corridors), and of course turbolift scenes allowed for private conversations before they had the idea of a ready room. So it was a necessary break from reality.

 

[Laura Cynthia Chambers]

Starfleet psychologists put them in because they provided the necessary time for someone to get their head in the game - they found it eased the mental transition from off-duty to on. Most of the time, when there isn't an emergency, it's okay to take a few extra minutes to get where you're going.

Aren't there other such designs made for that purpose in the real world? Less advanced because it's more restful for the person using it than the tech shortcut?

 

[Christopher]

Most of the time, when there isn't an emergency, it's okay to take a few extra minutes to get where you're going.

Don't you have that backward? Surely walking up or down stairs or climbing a ladder takes more time than riding an elevator, especially a "turbo" one.

Back in high school and college, I played around with a bit of starship design, and I had the idea that the decks would have ramps connecting them and the crew would get around with bicycles.

 

[Just a Bill]

I briefly flirted with the idea of ultra-fast, fixed-destination, intra-ship transporters. Imagine small clusters of closely-spaced pads at key locations (bridge, sickbay, hangar deck lobby, a central point on each deck...). Most are labeled with specific key destinations, typically ones on parts of the ship farther from the starting point to maximize the time-efficiency of beaming vs. walking/climbing/turbolifting. One pad in each cluster is always marked EXIT (don't ever step on that one or you'll trigger an alarm and clog up system throughput).

If you're on the bridge and need to go to sickbay, you step on the bridge's SICKBAY pad and it immediately transports you to sickbay's EXIT pad (as soon as the previous traveler, if any, has stepped off at that end). Beaming is quicker than usual because certain general-purpose transporter safety checks are unnecessary, all the distance and momentum deltas are pre-calculated for that fixed destination, environmental conditions at the other end are already known ... the main thing that needs to be checked at the destination is simple vacancy of the EXIT pad. So this can all be automated and optimized for speed.

The pads are close together because the sole function is rapid (and routine) intra-ship crew deployment. There's no general-purpose elbow room for unloading Tantalus crates or hoisting Kollos between antigrav units or slinging an unconscious Administrator Hengist over your shoulder. And there's no walk-and-talk happening here: transport is one person at a time, like queueing up to walk through the airport scanners, but quicker. (And you don't have to take your shoes off.)

This idea's inspiration is a basically mash-up of the small two-man transporter on K-7 with Larry Niven's sidewalk jump squares. Can't remember which book that was in, though; too many decades ago.

 

[Christopher]

This idea's inspiration is a basically mash-up of the small two-man transporter on K-7 with Larry Niven's sidewalk jump squares. Can't remember which book that was in, though; too many decades ago.

You're thinking of the stepping disks from the Ringworld books, the teleportation technology used by Pierson's puppeteers. Humans used enclosed transfer booths, like the ones in Niven's other, non-Known Space teleportation series.

I think the kind of "step through and get instantly beamed" transporter you're talking about was glimpsed in the first episode of Picard.

 

[Laura Cynthia Chambers]

Don't you have that backward? Surely walking up or down stairs or climbing a ladder takes more time than riding an elevator, especially a "turbo" one.

Sure, but it might be less direct and impeded by other lifts crossing its path. You may have someone wanting to go down the same ladder you want to go up, but less likely to meet someone climbing horizontally across the path of your vertical ladder.