List of DB 605A engine construction numbers?

[schwarze-man]

Hi everyone,

I have been able to study the relatively small number of DB 605AS engines with their engine serial numbers and the / assembly number ( /AS number) details highlighted by Tomislav. The basic background is that the first detailed flight test report of a Bf 109 G-AS that I have was on 22.12.43 with engine number 00702626. The engine serial corresponds to a build date of mid October '43 and the two month period before the flight test seems to probably represent the minimum that might be seen between engine build and flying at that time.
A point that can be seen on two of the engine data numbers is where the /AS number is out of sequence to the normal engine serial number. Here, I presume that the /AS number was allocated after construction of the complete AS engine. Because of this, it would happen that engines with delayed completion would be allocated a later /AS number than their serial number would suggest. So, an engine might have a later /AS number and where this appears out of sequence, it indicates that the engine was delayed before being completed as an AS and given a /AS number.
This does not really mean to apply to later possible "rebuilt" engines. That is a different question that I don't have info about, yet.
So, in particular, we see engine 00704581/346 which seems to be strange compared with 00705160/106, an engine number 579 later but with an /AS number 240 earlier. I think the situation here is that engine 04581 was delayed and it was completed as an AS engine about six weeks later.
Another possibility is errors in data. However, this does not seem to be a real issue and, the data is pretty solid for what I will propose.
So, my basic proposal is that the initial build of DB 605 AS-0 engines was a short run of 100 engines built in October '43. 00702626 would be an early engine in that block. The Flight test paper was compiled by Messerschmitt Augsberg on 22. 01. 44 and the positive performance improvement seems to have led to further engine/airframe production decisions.
The next batch of DB 605 AS-0 production started about end Feb '44, with engines at about 00705000. The first in the data is 00705160/106. Production at Genshagen was very high at this time, averaging about 900 DB 605 engines per month.
It is possible to calculate different average figures using different combinations of these statistics but, the average over the whole period from engine 00705160/106 to 00709767/1720 gives 4,607 DB605 engines produced, of which 1,614 were AS versions, which is 35% of production end Feb '44 till mid Aug '44.
The AS engine production continues after this point but, unfortunately I do not have the /AS numbers to help. However, I believe that this pretty much covers the very important stage of DB 605 AS engine production, up to late summer at Genshagen. DB 605 D versions were coming along at that stage.
Also, what happened with the later AS version production is another subject!
The data used is covered by the AS numbers given. There are later numbers up to 00711041, but without /AS number.
I hope this is useful to some!

Cheers

SM

[Matti Salonen]

My friend Pentti Manninen is still unable to log in to this site and has therefore asked me to forward the following:

"Regarding the DB 605 AS Baureiche 0 there is one interesting original documentation in the Finnish Air Force Museum archive collection.

With the FinnAF served two DB 605 AS engines WNr 007 0 7759 and the WNr 708251. The last mentioned was lost as German property and transferred to the Soviet Union, but WNr 007 0 7759 served FinnAF also post war time.

The WNr 007 0 7759 was assebled by Genshagen and installed into Bf 109 G-6AS WNr 163974 (FinnAF MT-463). This DB 605 AS was marked with overhaul time 100/2 on date 25.4.1944. The Lebenslaufakte WNr writings states also the following different styles: WNr 845 (00707759) and 00707759 (845), DB 605 AS Baureiche 0.

This DB 605 AS WNr 007 0 7759 Lebenslaufakte survives still with some dozens of plain DB 605 A-1 original documents. Some rarities are included as KWM 006 FIAT RA 1050 RC.58I Tifone:

540 48420
708 48588
874 48754
888 48768

and two more Tifone WNr of which WNr I do not have readily available.

Link to museum site and contact e-mails:

https://ilmavoimamuseo.fi/yhteystiedot/

Pentti Manninen"

Matti

[schwarze-man]

Originally Posted by Matti Salonen

My friend Pentti Manninen is still unable to log in to this site and has therefore asked me to forward the following:

"Regarding the DB 605 AS Baureiche 0 there is one interesting original documentation in the Finnish Air Force Museum archive collection.

With the FinnAF served two DB 605 AS engines WNr 007 0 7759 and the WNr 708251. The last mentioned was lost as German property and transferred to the Soviet Union, but WNr 007 0 7759 served FinnAF also post war time.

The WNr 007 0 7759 was assebled by Genshagen and installed into Bf 109 G-6AS WNr 163974 (FinnAF MT-463). This DB 605 AS was marked with overhaul time 100/2 on date 25.4.1944. The Lebenslaufakte WNr writings states also the following different styles: WNr 845 (00707759) and 00707759 (845), DB 605 AS Baureiche 0.

This DB 605 AS WNr 007 0 7759 Lebenslaufakte survives still with some dozens of plain DB 605 A-1 original documents. Some rarities are included as KWM 006 FIAT RA 1050 RC.58I Tifone:

540 48420
708 48588
874 48754
888 48768

and two more Tifone WNr of which WNr I do not have readily available.

Link to museum site and contact e-mails:

https://ilmavoimamuseo.fi/yhteystiedot/

Pentti Manninen"

Matti

Thank you very much Matti and also please thank Pentti!

The details of the AS engines are very good, and I thank you for the precise numbers. So, I think these two AS engines fit closely into the previous information. The first engine 00707759/845 fits both the production number sequence and the /AS number sequence. The other engine will undoubtedly have been 00708251 ( the /AS number would have been around 1050).
The date of 25.4.44 for the overhaul life recorded info seems slightly early on my engine build numbers (about a month) but, it depends when that was set down, I just don't know exactly how the administration of these details was done.
So, the overhaul life 100/2. The DB605A-0 (Zero series) had a similar life. This would mean "100 hours to major overhaul in two parts with part overhaul at 50 hours". This was an initial "life" for a zero series and would be further defined with experience.
So, good extra data to go with the previous AS info!

Now, the other Italian DB 605A data. Yes, very nice. It certainly looks like the Italian production is much greater than I have seen written before.

Many thanks!

Chris

[Matti Salonen]

The Finnish Air Force interpretation for the overhaul life 100/2 was different. According to them that meant "100 hours to major overhaul and only two cycles allowed (maximum 200 hours running time)". The engine 00707759 was in the aircraft 125h30' before removal. That was exactly 100 h plus 25 % extension due to good engine condition.

Matti

[schwarze-man]

Originally Posted by Matti Salonen

The Finnish Air Force interpretation for the overhaul life 100/2 was different. According to them that meant "100 hours to major overhaul and only two cycles allowed (maximum 200 hours running time)". The engine 00707759 was in the aircraft 125h30' before removal. That was exactly 100 h plus 25 % extension due to good engine condition.

Matti

Hi Matti,

That is very interesting. I can understand if War emergencies caused engine overhaul delays, and different National operators could apply their own standards. However, I think that you wrote that the Genshagen production plant specified the "100/2" overhaul requirement?
The German data from Mercedes-Benz does not specify life-extensions, so that is a question? Beyond that, the Luftwaffe DB605A overhaul manual DLuftT. 3605A-B 0 und 1 is quite specific about the overhaul life and requirements of the DB 605 A, and the 0 (zero) series engines have a specific 100 hour Grunduberholung limit, with a Teiluberholung every 50 hours, and with no restriction on total number of rebuilds. So, I am interested if you have more data about this?

Cheers

SM

[schwarze-man]

Sorry to jump back in,

I can be very specific about the DB 605 A overhaul requirements because they are laid down in three different original German documents.
It is fair to say that "this is the DB 605 AS, not the DB 605 A" but, the documentation for the DB 605 AS says that, it is "the DB 605 A fitted with a DB 603 A supercharger". Actually, this is not precisely correct either.
Nonetheless, the original DB 605 AS documentation specifically lists the DB 605 A information as applicable, including the DB 605 AS parts list that is only an addendum to the DB 605 A parts list, to which it refers.
There is more information about this but, I am interested if you have a confirmation if the Finnish engine life was;
"100 hours to major overhaul and only two cycles allowed (maximum 200 hours running time)" ?
The German servicing cycle was much different to this.

Cheers

SM

[Tony Kambic]

MM44643 engine ( DB601) is on MM9476.

Just about the stamping on MM44643 is another number: NC 0517


Steve, you know where I got this I trust.

Tony

[schwarze-man]

Great info Tony. From the C.202 I believe. That number is very close to some of those in the post #112 from Tanzebau. The additional stamping NC 0517 might have a relationship to the local production numbering.

Cheers

SM

[Tony Kambic]

You are correct Schwarze-man.

Hope that number fits into the list properly.

Tony

[Matti Salonen]

The Finnish Air Force normally followed the OEM established maintenance schedule. They also used the basic information in D.Luft. 3605A – B, but in locally modified form.
In Finland for DB 605 there was a 110 hours limit for a partial overhaul and 220 hours limit for complete overhaul.

Because in Finland engine running time was calculated adding test runs and ground operations to the flight time we used a life-extension based on condition of the equipment (established on a case-by-case basis, maximum 25 % for engines and 10 % for airframes).

If in the Luftwaffe system only flight time was noted in the engine running time, the Finnish model would not differ much of the Luftwaffe system especially, when D.Luft. 3605A – B does not state an exact overhaul limit but is somewhat flexible: “Nach etwa 100 Betriebsstunden” for series 0 and “Nach etwa 200 Betriebsstunden” for series 1. How much “etwa” means in running hours?

From our point of view it seems that in D.Luft. 3605A – B specified limits are a general basic rule and in real life that was interpreted by different repair shops on a case-by-case basis depending on the engine series, modification status and condition.

We have over 220 original DB 605 A –engine Lebenslaufakten in our Air Force Museum and they give a good although limited view of the repair methodology of DB 605 in Germany.
- For example 25776, which in the beginning had 100/2 overhaul limit, after repair in Germany got a new limit 75/2. (Does this mean that this engine should be sent to repair shop for partial overhaul after only 37,5 hours in the aircraft?)
- 26887 was originally DB 605 B-1 and had in the beginning an overhaul limit 75/2. It was modified to A-1 in 22.01.1943 and probably got the normal overhaul limit 100/2
- a new 76136 got in 29.01.1942 50 hour running time, but after overhaul at 56 hours in 19.09.1943 it got allowable running time up to 253 hours (overhaul limit 200 hours)
- 76782 had got in the beginning an overhaul limit 100/2, but after overhaul at 56 hours running time in 02.12.1942 it got a new allowable running time up to 252 hours (overhaul limit 200 hours). Then after a new overhaul at 125 hours in 29.07.1944 it got a new allowable running time up to 321 hours (again overhaul limit 200 hours).

According to our interpretation 100/2 in those documents means two 100 hour periods, but if you have a document, which confirms other meaning, we’ll be happy to accept that.

Unfortunately we have not yet found any document covering the content of the partial overhaul. At least it cannot be done in the fighting unit, but the engine has to be sent to a repair shop. During the war we have not found in Finnish Bf 109 any engine removal due to partial overhaul requirement, but all removals have been due to a crash or engine damage. Some of these engines had after that a partial and some complete overhaul at the Luftwaffe or Finnish repair shop.

These Lebenslaufakten include some interesting engines.
- 78874 was originally built in November 1942 as DB 628 V19 and used only 4,5 hours before being sent to overhaul. During the overhaul it was modified to DB 605 A-1 standard and got a new allowable running time up to 204 hours (overhaul limit 200 hours). This engine was sent to Finland in February 1944
- 007 00003 was similar case
- 100079 was built in July 1942 as DB 605 X and seems to have been part of DB 610. Was used in He 177 A-3, Werk.-Nr. 355065, but sent for overhaul 12.02.1943 after only 8h55’. During overhaul it was modified to DB 605 A-1
- 21077 was similar case.

DB 605 engine family has been very interesting and it would deserve an exhaustive study.

Matti