[Grammar] Use of articles with homogeneous sentence parts

[Jack8rkin]

Hello!
The question is: Should I detemine each homogenous sentence part if the first part is determined with the definite article in structures like this:

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1. The small non-rigid airship, or dirigible balloon has a faired envelope...​

2. Adjustment of the nuts and springs is accomplished in a similar manner as for the carriage bolt type installation...
3. The reactor vessel, PCU vessel and cross-vessel should be inspected...
4. The manufacturer, fabricator, or installer shall assure that all equipment calibrations... are performed.

 

[Barb_D]

You do not need to repeat the article.

However, in your first sentence, you need another comma after "balloon."

 

[Jack8rkin]

The first example was taken from the textbook called Aerodynamics by N. A. V. PIERCY, 1947, London. It reads like:

The small non-rigid airship, or dirigible balloon (Fig. 7 (a)) has a faired envelope whose shape is conserved by excess gas pressure maintained by internal ballonets which can be inflated by an air scoop exposed behind the airscrew.

Maybe the comma is omited because of the bracket/parentheses?​

 

[Tdol]

Probably- things are piling up in that sentence- double brackets, alternative terminology...

 

[Jack8rkin]

Quite a complicated sentence, true. Technical language...