隔てること一万五〇〇〇メートル

[thetazuo]

琴里がいるのは、士道たちのいる天宮アリーナから縦方向に距離を隔てること一万五〇〇〇メートル、夜闇の中に浮遊する空中艦<フラクシナス>の艦橋だった。

Hi. What is the function of the こと here? I have never seen the construction “verb+こと+数量”. Is it a fixed pattern?
Thank you.

 

[Techref]

Yes, you would need the こと to nominalize (名詞化) 隔てる into a noun.
That is where you can define the distance of 15000m.

Sorry if this explanation is poor, but I hope you could grasp it.

 

[SoLaTiDoberman]

I think it might be easy if you think that は (or に関しては、については）is abbreviated after that こと in this kind of expressions.

こと works to nominalize the previous part.

動かざること山のごとし。(動かないことは、山のようだ。不動性は、山の様である。）
Not to move is like a mountain.
Immovability is like a mountain.

天宮アリーナから縦方向に距離を隔てること15000 ｍ、・・・
＝距離を隔てることは、15000 ｍで、・・・
＝隔てる距離は、15000 mで、・・・
=To keep the distance vertically from the arena counts for 15,000 m.
=The distance is 15,000 m.

AことB
＝　Aであることは、Bです。
＝　［A=B］
B is not necessarily numbers(数量）.

 

[thetazuo]

Thank you both.

 

[Flaminius]

This construction was, presumably, developed for translating an Ancient Chinese expression. I don't know how wide this expression or similar ones are used in AC, but 淮南子 uses 居一年 just as it is used in Japanese today (to be exact, Japanese used this as a material for its own new construction).

居一年，胡人大入塞
The traditional kambun style translates this into:
居ること一年、胡人大いに塞に入る。

Again, I don't know if other Chinese verbs can take a quantifier object and make an independent clause. Nor am I to suggest 淮南子 is the direct source of this Japanese construction. Having said that, the Japanese construction seems to be used with a variety of verbs. Two more examples than have been mentioned are:
今を遡ること87年、私たちの祖先はこの大陸に新たな国家を建設した。
歩くこと2時間、登山家たちは山頂に到着した。

 

[thetazuo]

Thank you, Flaminius. I didn’t know the construction was derived from Japanese translation of Ancient Chinese. 勉強になりました。