Talk:Synchronization gear

Redundant?

Someone replaced this word with "unneeded". This is an English language encyclopedia - and in this editor's opinion people not fully conversant with that language should really restrict their editing to matters of fact rather than style. I have nonetheless rephrased the sentence to avoid the word "redundant", while maintaining unstilted Engish. Soundofmusicals 14:35, 20 July 2007 (UTC)

Constantinesco

I went to school with the son of Constantinesco. He was reputed to have invented the device to allow guns to shoot through propellors. You mention him in the third paragraph from the end. Who was he, who did he work for, when? Did he have priority over the others you mention?

There is an article on the Constantinesco synchronization gear in the September 2005 issue of Aeroplane Monthly. It says:

The final British gear was known by the name of its inventor, the brilliant Rumanian engineer George Constantinesco (1881–1965). His system, known as the "CC" gear, was so superior that it eventually replaced all others in the RAF and was also used overseas.

So his wasn't the first, but it was the best. I've updated this article with the new (to me) info but Constantinesco's system deserves an article of its own. Geoff/Gsl 09:57, 22 November 2005 (UTC)

Why synchronized?

I came here to find out WHY it was useful to have synchronized guns. Why didn't they just move the guns a bit further apart so they fired clear of the propellor blades? This article implies that keeping the guns close to the pilot provided some benefit, but does not describe the benefit.

Rahul

The guns were on the fuselage because that was strong enough to take them, they are fired by a mechanical linkage and any jamming could be cleared by the pilot. GraemeLeggett 08:25, 18 May 2006 (UTC)

The French tried something like that by mounting a Lewis gun on the upper wing of the Nieuport series of scouts. The problem was the Maxim-type guns couldn't be mounted that way as there was no place to put the belted ammunition and the drum of the Lewis gun didn't hold many rounds, causing the pilot to have to preform some pretty acrobatic maneuvers to reload while trying to fly the plane. The later Nieuport series scouts like the 21 used 2 maxim type guns mounted on the fuselage. Lepeu1999 19 June 2006

This system also makes it significantly easier to aim, as the plane itself is in essence the aiming gear. With offset guns, either above or to the side of the fuselage, compensation must be made for the positioning of the guns which are necessarily mounted at an angle in order to obtain a firing solution on a target directly in front of the plane. This complicates aiming significantly, as not only does the pilot have to compensate for the elevation of the target (as with a standard firearm or naval gun), but also the horizontal position in a manner peculiar to the mounting of the gun. Lining the plane up and squeezing a trigger is much simpler! njan 19:55, 19 September 2006 (UTC)

Error In Diagram

Has anyone else noticed that the direction that the cam is indicated as moving is in error? It conflicts with the text and doesn't make sense for it to be moving counterclockwise.68.19.25.163 05:05, 21 September 2006 (UTC)

"Interrupter" vs. "synchronization" citation

Can someone provide the citation for the statement that what is commonly called an interrupter gear is really a synchronization gear? Even in academic papers, it seems extremely common to use the former term when discussing the mechanism that this article says is actually the latter, so it would be nice to cite the definitive explanation of which is which. Sarcasmboy 22:54, 24 July 2007 (UTC)

It IS properly named a "synchronizer" !!!

Dear Sarcasmboy:

The PIPE here...a VERY serious student of aviation history...and in the WW I AERO quarterly aviation history journal, there were a series of three articles, authored by the now-passed Canadian aviation historian Hank Volker from Quebec, that dealt in incredible depth on the history and technology of machine gun/autocannon synchronization through the arc of a spinning propeller.

The current website for the WW I AERO journal...which IS about to go to "online-only" content...is at http://www.ww1aeroinc.org/index2.html , and below is the listing of Hank Volker's articles on MG/autocannon synchronization's history and technology in the WW I AERO publication's past issues...

WW1 Aero No.137 (August 1992) pgs. 42-61 Part I Synchronizers: firing through the prop: origins - a historical survey

WW1 Aero No.138 (November 1992) pgs. 74-83 Part II Synchronizers: firing through the prop: machine-gun synchronizers and "interrupters" (the article series consistently uses ONLY the term "synchronizer" throughout all three parts of it!)

WW1 Aero No.142 (November 1993) pgs. 47-62 Part III Synchronizers. Firing through the prop: automatic guns for synchronizers.

All three of these articles are still readily available as reprints from WW I AERO, at their Red Hook, NY mailing address.

Also, I quite seriously think that the "interrupter gear" title for this page is COMPLETELY unsuitable, and that it SHOULD be retitled, at the earliest possible time, in such a way that the word "synchronizer" totally replaces ANY mention of the word "interrupter" for the description of the Wikipedia page and subject it is concerned with.

Yours Sincerely,

The PIPE (talk) 22:40, 7 August 2009 (UTC)

Hi Pipe - the problem I see with this is the way the original article was organised to cover "interrupter" (in the sense of a "gear designed to prevent damage to an aeroplane by its own armament"). It should be noted that naval ships also need interrupter gears to prevent gunners following quick moving targets (like aircraft or fast torpedo craft) from damaging their own ships. In this sense a synchronisation gear is a subspecies of interrupter - designed to prevent a fixed gun from damaging an aircraft's propeller, as opposed to a movable gun being prevented from damaging an aircraft or ship (what most interrupter gears do!). As I see it the article on the "Interrupter gear" should really cover all kinds of gear designed to protect ships and aircraft from their own armament (including at least a summary about propeller synchronisers) - with, perhaps, a further specialist article about propeller synchronisation. What thinkest thou? (I will write this as my next "project", subject to your comment, if any) --Soundofmusicals (talk) 23:21, 7 August 2009 (UTC)

Dear SoundofMusicals:

The PIPE here again...one possible answer MIGHT be to create a totally separate Wikipedia page, named Gun synchronizer (aircraft), that would solely cover the aviation-ONLY gun synchronization issue that Hank Volker covered in his comprehensive three-part article in WW I AERO over fifteen years ago. I'm quite certain that I still have these three past issues of WW I AERO stored away somewhere here at home, and when I find all three of them, I'll certainly start work on creating that separate page.

Two "parallel" ways of thinking of a machine gun/autocannon synchronization system, starting with Fokker's original Stangensteuerung unit on the Fokker M.5K/MG quintet of pioneering Eindecker example aircraft that it debuted on, is to think of the "engine essentially firing the gun"...and in a manner of parallel thinking, it could also be said that a machine gun/autocannon synchronizer works to synchronize the operation of TWO separate "internal combustion engines"...with the larger one powering the aircraft's propeller (usually a four stroke engine), and the smaller one being a "single-stroke engine" (the aircraft's forward firing weapon(s) itself), so that the operation of the "single-stroke engine" is "slaved" to the four-stroke engine through such a synchronizer, to avoid the problem of the single-stroke engine preventing the four-stroke engine from doing its work of moving the aircraft forward in the first place.

WW II defensive bomber turrets certainly DID have firing "lockout" devices on them to prevent the turreted defensive armament from shooting off essential parts of the bomber's airframe itself, and I readily suppose those sorts of devices could be considered "interrupter" setups of a sort...but the central issue I'm discussing here (as well as what Hank Volker's three-part article was centered on) is how any fighting aircraft, starting very early in WW I, could SAFELY fire its forward-aimed weaponry through a propeller's arc of rotation...this REQUIRED a "synchronization" device of some sort...and what a separate Wikipedia page entitled Gun synchronizer (aircraft) would be able to address, that could easily have QUITE a bit of the content of Hank Volker's 3-part article as a basis, and be a much more concise and definitive piece of the issue I've mentioned here.

Thank you and Yours Sincerely,

The PIPE (talk) 16:59, 8 August 2009 (UTC)

Good idea - I will parallel this by rewriting the "Interrupter" article! I have made a token start on this by re-writing the initial definition more accurately. --Soundofmusicals (talk) 02:42, 9 August 2009 (UTC)

A few thoughts on the "End of Synchronization" section

a) The disuse interuptor gear or fuselage-mounted guns was a US and British speciality. There were lots of piston-engine fighters, even from 1940 on, with interruptor gear and guns firing through the propeller hub. Some examples German: BF109, FW190, Ta152, Do335 Italian: Macchi C.205 Japanese: A6M, Ki-84, Ki-100 Russian: La-5, La-7, Yak-1, Yak-7, Yak-9, Yak-3 Not to forget the P39 / P63. Also, with the dawning of the yet age, even the US and Britain reverted to fuselage mounted guns. Both the P-80 and the Gloster Meteor and most subsequent jets have their guns mounted in the fuselage.

c) AFAIK the main reasons for the disuse of interruptor gear were:

• Cost saving
• The low rate of fire of the M2, which would have been further lowered if the guns were synchronized

b) Gun convergence is not a solution, but a problem. The max. effective range of harmonized guns is only about 2x the convergence range. Also, the effectiveness decreases sharply over distances shorter than the convergence range. In contrast, the effectiveness of straight-firing guns is only limited by their ballistics.

d) Guns mounted on or near the fuselage also have their mass nearer to the aircraft's center line, therefore resulting in an improved roll rate.

e) None of these factors have anything to do with gunsight technology. —Preceding unsigned comment added by 208.48.159.253 (talk) 09:39, 24 July 2008 (UTC)

Questionable statements in the second and third paragraphs:

two guns were no longer enough

The Russians seem to completely disagree. Also, the Axis powers went for more powerful guns instead of more .50 cals like the Americans. The Russians even retained this policy after the war because their testing indicated that a powerful slow-firing gun performed better than a fast firing weak one, just compare the Gryazev-Shipunov GSh-30-1 and the M61 Vulcan.

Since it was never practicable to mount more than two synchronized guns in the forward fuselage

There were 3 gun versions of the La5, 7. The La-9 had 4 guns, the La-11 3 guns by default.

additional weight

The MG151 used an electrical system. I do not now exactly how much additional weight this meant, but I highly doubt it was noticable

became increasingly unattractive

How so? See the list mentioned above.

In fact even the old (and highly problematic) idea of mounting a cannon to fire through the centre of the propeller hub was revived to this same end

This idea was not "revived", for instance the Germans tried this right from the beginning with the 109. Also, this has little to do with synchronization, as there were two major benefits: a) The engine acted as a sturdy mount point. Look up the warping problems with wing-mounted Hispanos b) The high mass of the engine alleviated the effect of the guns recoil, therefore providing better accuracy.

Please note that the statements in these two paragraphs are US-specfic and in their current general form factually incorrect. Also they are not verified by citations. IMHO these two paragraphs should either be removed altogether or modified so that they cleary distinguish between US,British / rest of the world developments. I have seen quite some activity on this section in the history so I'm not changing anything without getting more opinions --Holzhackerbua (talk) 08:10, 17 April 2009 (UTC)

Lots of intestesting stuff there - although the following is also relevant.

1. Wing mounted guns were mainly put there to avoid the propeller and thus the need for synchronisation. (Other reasons included lack of room). Jets like the Meteor and ME.262 had no propeller, and wing mounted engines (hence more room in the nose). Of course they used "fuselage mounted" guns. NOT relevant here - since we are talking about synchronisation, and aircraft without propellers have nothing to synchronise!!

2. The Russians (and Italians) did indeed persist in twin gun armament for longer than the others - they also designed and build biplane fighters long after everyone else had adopted the low or mid wing monoplane. The fact is that in both respects they were very simply backward looking.

3. Everyone moved towards heavy calibre weapons from about 1939 onwards. But these weapons were never amenable to synchronisation - the Russians tried synchronising nose mounted cannons - and some marks of the FW 190 had synchronised cannon (mounted in the wing roots) but apart from these isolated examples - practically all cannon armament in prop driven fighters was wing mounted and therefore not very relevant to this article.

4. Apart from a few Russian examples from the 1940s, and an experimental variant of the Fokker E.III of 1915 - no fighter ever carried more than two synchronised guns. Significantly, the Germans, and even the Italians and Japanese (and to a large extent the Russians) all persisted with two synchronised guns - mounting any additional guns in the wings.

5. The idea that electrical systems in the 1940s were necessarily "light" needs qualification! They were in fact often heavier than mechanical or (especially) hydraulic systems, as well as being inherently far less reliable. Put modern elctronic miniaturisation completely out of your mind! Even electric motors were much bigger and heavier than modern equivalents of similar power. In any case, in any fighter every kilogram counts. That applies even today - much more in the 1940s.

6. Mounting a cannon to fire through a hollow propeller hub dates from 1916 and the SPAD S.12 (among other aircraft). It was revived in the late 1930s early 1940s (in the U.S. as well as Germany and Italy) but proved as problematic as it had in 1916, in spite of the obvious advantages you mention. It is mentioned here mainly as another attempt to avoid the need for synchronisation, while maintaining the advantages of centrally mounted weapons.

7. What the article essentially says at this point is that synchronisation persisted until the era of jet fighters, but it was already on the way out. This basic statement is not contradicted by anything you say! Even in Russia, where it persisted the longest, synchronised guns form a diminishing portiion of the total fire power of a fighter.

8. Many of your other points (such as the drawbacks of wing mounted guns' needing to be "harmonised") are already covered!!

HAVING SAID ALL THIS!!! The article is obviously not perfect - it "grew" rather than being written by one person and is a bit on the scrappy side, for instance. You may well be able to improve it. I totally agree, for instance, that it needs more references. Please get GOOD sources (there are a lot of rubbishy aviation books out there) for any major changes. --Soundofmusicals (talk) 01:36, 18 April 2009 (UTC)

Twin engined types

Not really relevant - these types had always been around - and obviously had never needed synchronisation!!

Succeeded of failed to burn his plane?

In the description of the events of 18 April 1915, Roland Garros (aviator) page claims Garros succeeded in burning the aircraft, while Interrupter gear claims Before he could burn his aircraft, he was captured.... Whomever can cite a reliable source on this, please correct the misleading page. —Preceding unsigned comment added by Ahtih (talk • contribs) 20:01, 1 February 2009 (UTC)

I have modified the page concerned (although without a cite). This is not a contentious point really - if the aircraft was successfully burned Garros would have no part in the story of the Fokker synchroniser, would he? --Soundofmusicals (talk) 01:47, 18 April 2009 (UTC)

Redundant

This is the perfect word to describe the state of the art in re. gun synchronisation after the development of jet (propellerless) fighters. "Unnecessary" is nearly as good - in fact the two words mean nearly the same thing - but not exactly. "Redundant" has the added nuance of something that used to be useful but has become unnecessary. A redundant employee is one whose continued employment can no longer be justified, for instance. A redundant body organ is one not required by an organism, but which was useful to its distant ancestors. If synchronisation was unnecessary it would never have been applied in the first place. "Obsolete" on the other hand is quite wrong - something that is obsolete needs to be replaced with something up-to-date. Gun synchronisation was simply discarded altogether, not superseded or replaced by new technology. --Soundofmusicals (talk) 03:18, 4 December 2009 (UTC)

I think the term for the body organ you describe (for example, the appendix) is "vestigial" not "redundant". The nuance of "redundant" is that it's not needed because it has been replaced by or is a duplicate of something else that fits its niche (firing the second secretary after company merger because you already have one; firing your only secretary because the company does not require any sort of secretarial services would be because the position was obsolete not redundant). The gear wasn't removed because, for example, electronic firing mechanisms were added that were a more accurate way of avoiding the propeller blades. The whole system and anything like it would serve no purpose now because the whole issue is irrelevant. "Not needed" or "unnecessary" seems better here. DMacks (talk) 11:11, 28 June 2010 (UTC)

MORE on "end of synchronisation" section

While it is certainly true that some of the early Allison engined Mustangs were the last U.S. aircraft to have synchronised guns, we really don't need what would inevitably develop into a list of fighters with or without synchronised guns here - once we described one illustration or exception to the generalities of this section it would just get out of control and we'd have another instance of the "how can you mention THIS fighter without also describing THAT one". (viz. the list of Baha'i prophets and "well-known" musicals). Easier and more stable to leave this particular generality unillustrated. --Soundofmusicals (talk) 23:11, 27 June 2010 (UTC)

So, while I am not supposed to mention the P-51 because that might set off some kind of "chain reaction", mentioning specific types of Russian fighters is okay, according to you. Interesting. No need for further arguement I'll just leave this almost entirely unreferenced article alone.Minorhistorian (talk) 10:47, 28 June 2010 (UTC)

I'd certainly support the P-51 being included. I wasn't even aware it had ever used fuselage mounted MGs.

AFAIK, everyone had always favoured wing-mounted armament (for several reasons, not just avoiding interrupter gear) and it was lack of mechanical strength that prevented this. When aerodynamic loads on wings started to require a spar structure anyway that could also cope with firing loads, the movement to wing-mounting was a natural progression. So why hadn't the P-51 followed this trend anyway? What was the reason for this somewhat backward-looking approach? Andy Dingley (talk) 11:03, 28 June 2010 (UTC)

Not that simple Andy - the fact that when props disappeared so did wing guns shows that there might just be a direct causal link between the two! Read the remarks higher up this page!! As for minor historian - I agree we could improve this article with more references - if you know some good references by all means add them. I am at a bit of a loss to determine what this has to do with adding barely notable (and incidentally also unreferenced) matter? If the article is not that good (I tend to agree) then surely we need to be more careful about the notability of what gets added, not less?

Most Allison Mustangs and all Merlin ones had only wing guns so this is simply not very notable - at least not outside the P-51 article itself. For that matter the Hawker Hurricane prototype had provision for some of its guns to be in the nose, too - although by the time it was completed they had decided that all guns in production a/c were to be in the wings. And of course early P-40s had a pair of synchronised guns in addition to its wing mounted ones. It would be quite easy for this (less than brilliant already) article to degenerate into a list of types that did or did not use synchronised guns if we started down this line. If you seriously think this SHOULD be the case then by all means argue your case here!

On the other hand we can (and do) mention the first and the last types to fire synchronised guns in action. I think this is at the very least just a little more notable. Again, if references to the Eindecker and the Korean War Russian prop. fighters are felt to be irrelevant, then argue a specific case for it here. --Soundofmusicals (talk) 04:36, 29 June 2010 (UTC)

Warships

The article says this is used on warships in the intro sentence, but nothing else is said about it. This needs expansion. 76.66.192.55 (talk) 04:42, 15 July 2010 (UTC)