Talk:Aerojet LR87

Number of nozzles

See Talk:LGM-25C Titan II#One lump or two. Andrewa (talk) 05:29, 13 July 2013 (UTC)

That discussion has been dormant for some time. Meanwhile, our articles on the LR-87 and the rocket missiles that it propelled remain woefully inconsistent. And really authoritative sources seem surprisingly hard to find.

There are I think two possibilities:

• Take the risk of WP:OR and treat all versions of the LR-87 as one engine with two nozzles.
• Be pedantically WP:NPOV and take no stand either way.

Either way requires a considerable amount of work to implement, so I'd like to have a strong consensus on which to pursue.

It seems clear to me that neither a single-nozzle nor single-chamber version of the LR-87 has ever been built. In all versions, several vital components are shared between the two chambers and nozzles in such a way that the two can only be fired as a single unit. To scale these systems down to support only one nozzle has never been attempted.

However, one now-inactive editor claimed that the LR-87-5 was a single chamber engine, which was fitted as a pair on the Titan II first stage. That is in contrast to the LR-87-3 of the Titan I, which was a two chamber engine with shared turbo-pump.... [1] This seems quite widely believed, but despite considerable effort we have no good sources to support it.

An IP with no other contributions has said It never occurred to me to consider it a single engine. We always referred to them as "engines". To be precise (and having worked on them in the USAF, I know)...two thrust chambers and four turbo pumps (two per thrust chamber). That of course suggests that they are two engines, but they did share peripheral support systems. The hot gas generator (for pressurizing the propellant tanks) the lubrication system and the drive unit (a small reaction chamber where a negligible amount of propellant was reacted to drive the turbopumps for the thrust chambers) were critical parts of the engines. In that respect it is proper to say that since the thrust chambers could not operate independently, they must, therefore be considered a single unit. (my emphasis) [2]

That to me explains a lot. The in-house jargon was always engines, but the more considered opinion is that it's a single engine. All versions.

And of course we will always have well-meaning editors who take one look at the photo at left and say to themselves it clearly has two engines and "correct" the text to match. (I have the same trouble with the photo of my fretless ABG. [3]) From that point of view, it would be really good to have a clear conclusion to our discussion here.

See also RD-180 which is always considered a single two-nozzle engine AFAIK.

Comments? I have posted heads-ups at WikiProject Rocketry (which seems inactive) and WikiProject Aviation. Andrewa (talk) 02:04, 15 March 2014 (UTC)