'ab means have a length/height of, so you're describing the length and/or height of something. You're measuring it in its long dimension. If your ship is a rocket standing on its tail, and it's one hundred ujas from tail to nose, then it's perfectly reasonable to say wa'vatlh 'uj'a' 'ab Duj. But you wouldn't use 'ab to describe the height of a ship that is longer than it is high.
But that's exactly how 'ab was used on the Bird of Prey poster. Note that 'ab was used for the various heights of the ship despite that it's longer than it is high, and 'aD is used for the length.
wejvatlh loSmaH loS vI' vagh wej 'uj 'aD Duj Length: 120 M
HIvtaHvIS toQDuj cha'vatlh wejmaH Soch vI' vagh chorgh 'uj 'ab 'oH Attack Formation Height: 82.75 M
qughtaHvIS toQDuj HutmaH vI' jav wa' 'uj 'ab 'oH Cruise Formation Height: 31.56 M
SaqtaHvIS toQDuj wa'vatlh loS vI' jav chorgh 'uj 'ab 'oH Landing Formation Height: 36.46 M
I agree with diyongemallo.
How is a ship different from a table, really. It has a height ('ab) and a length ('aD) and a width (juch). It seems logical to me that the height would be expressed with 'ab, irrespective of whether the height is greater than the length or not (it could be a long low table, kind of like a long ship that flies horizontally and is longer than high, and distinct from a rocket that is more like an arrow/rope/staff, the length of which would be expressed with 'ab).
I disagree with the description in Tips & Notes that the length of a fence should be expressed with 'ab. How then would you describe the height of the fence? A fence has two significant dimensions. Any fence would also have a width even if small in comparison with the other two dimensions.
I think it could help learners understand these terms more easily if the terms could be explained in relation to one another, and that Tips &Notes should be edited at least to include 'aD and juch, if not also to remove the fence explanation which is confusing.
I have updated the description of 'ab in the Tips & Notes to read as such:
A note on the word 'ab. This word means "to have a height of ...", but may sometimes be translated as "to have a length of ...".
For something that effectively has one measurement or at least has a significantly greater measure in one dimension than in the other two (such as a pole or a rope), 'ab will give you the length of that greatest dimension. Klingons apparently imaging measuring such long objects standing on end, instead of lying down. Even for something that is never stood on end, if it is much longer than tall (such as a fence), you could use 'ab to give the length.
Where's everyone getting the idea that 'ab is used for the longer dimension of something where one dimension is longer than the other?
This is what we got from Okrand (msn, Oct. 22, 1997):
There are two words used for length: 'aD and 'ab. Both of these can be translated "have a length of," but they are used somewhat differently. 'aD is used in contrast with juch "have a width of" in measuring, say, a tabletop. 'ab, on the other hand, is used for (potentially) longish, skinnyish things (for example, spears) and also for heights.
Maybe people are confused because he put the meaning referring to longish things first, but 'ab basically always measures height. It's clear from the Bird of Prey poster, and from the other examples about spears, painstiks, and people. It's just that for spears and painstiks, Klingons think of them as being "tall" (standing up) rather than being "long", the way English speakers do.
height: 'ab (head to toe of person, top to bottom of starship or table, tip to other end of spear or painstik)
width: juch (one dimension of tabletop, presumably also wing tip to wing tip of starship)
length: 'aD (other dimension of tabletop, fore to aft of starship)
Note that a ship's height is expressed using 'ab, even though it's the shorter dimension compared to the length (fore to aft). 'ab does not always measure the greatest dimension. It only happens to do so for things that look like sticks.
A fence is nothing like a stick. Its height (from the ground to however high it reaches) is 'ab: the same dimension as that of a person standing next to it.
My intuition is that when Okrand talks about "longish, skinnyish things" he's thinking of objects with two particular characteristics: a) more than just "longer than they are tall", one dimension is a lot longer than the others, so the object can be thought of as approximately one-dimensional; and b) the object doesn't have a single established orientation with respect to gravity, so it isn't obvious which dimension would literally be it's "height". (A spear, for example, could be lying on the ground, leaning against a wall, or wielded at various different angles as necessitated by circumstance.) If an object has both these properties it's probably safe to use 'ab for its long dimension; if it has neither, you probably shouldn't, if I'm reading the situation correctly.
If we imagine a spaceship in the form of a long straight tube, which doesn't land on planets, use artificial gravity, or otherwise mark out one of its dimensions as "vertical", 'ab would refer to its long dimension, while in English I'd probably call it "long" rather than "tall". So in this case wa'vatlh 'uj'a'mey 'ab Duj could translate "The ship is one hundred ujas long".
I believe that this is (was?) a fairly pointless conversation. A newborn baby is called, "long;" I am called, "high." How many juches wide a person is, is measured at the shoulders or hips, depending on the person. So a newborn's height is measured through the chest or head (from a klingon's perspective). qar'a'. Yes, I understand that newborn babies aren't ships or fences. And in space, there is no up or down, so a spear is say, one inch tall (from a klingon's perspective).
I dig that you answered so quickly. And yes, I understand that. But by the time that someone can explain to me how a ship can be so many 'abmey long, I will have died of old age, and I will know already. (And yes, I was editing after you had answered me). Thanks for that.
Sometimes one language will use a term differently than a similar term in another language. Those differences and similarities are often worth exploring. While the result of this conversation may have led you back to where you started other people may be starting at a different point and may have changed their use of the words after reading this. Also this conversation led to us improving the tips and notes, so that was of great value indeed.