List of DB 605A engine construction numbers?

[Dénes Bernád]

Excellent overview, Matti! Especially your last sentence is noteworthy. I would gladly co-operate with a team who sets this goal, to be materialised in a book.

[schwarze-man]

Originally Posted by 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

Yes, Thank you Matti for a good reply.
I can answer with the German information that I have in a few days, and I have many answers for you.
It is great that you have so much detail of the individual engines. I think this must be very rare. I don't know of any German individual DB 605 engine records with such detail, unless anyone has knowledge of this? I presume that the records of the Finnish Air Force engines are more complete?
The production of DB 605 engines from the DB 610 units was quite considerable, as there were a lot of them available. However, usually the rebuilt engine had a different firing order, inherited from the DB 610. The RH "605 W" component would also need rebuilding with a complete replacement rear gearcase etc as that was a complete mirror-image assembly when fitted as a DB 610 unit.
So, I will answer your points ASAP.

Cheers

Chris

[schwarze-man]

Hi Matti,

Sorry to be slow responding. I will try to answer your points. First thing is that the German system is laid down in a fairly straightforward way but, the actual way that engine serviceability worked-out was more complicated. Also, I am not a German language specialist so, please forgive any mistakes!
The basis of my information is the interpretation of DB605 servicing for modern certification, using the original DB requirements.
Firstly, the overall servicing documentation was reasonably straightforward when the DB605 was first produced in 1941/42. The complicated engine had several levels of SERVICING documentation. Firstly, the D.(Luft) T. 3605 A-B, 0 u. 1 Handbuch covers the engine in moderate detail, including a servicing schedule. Here we find the engine has the 0 (zero) series and 1 (one) series. the 0 series are the early production that has a short servicing period. The 1 series is main production and has a servicing period about twice the 0 series.
Both series have the same daily, before flight and every 12.5 hour servicing.
Next, we find that the servicing at every 25 hours includes an oil change for the 0 series and a common, for both series, list of servicing items.
The schedule then introduces the concept of Teil-uberholung and Grund-uberholung (part-overhaul and full-overhaul) with the Grund-uberholung being nominal 100 hours for 0 series and 200 hours for 1 series. The Teil-uberholung being at half life and, the 1 series having an additional list of servicing at 50 hours ( where the 0 series has a Teil-uberholung).
Here, in the Handbuch, there are lists of work to be done, but the detail of the work is in a different document, the D.(Luft) T. 3605 A-B, 0 u. 1 Beiheft 1 Instandsetzungsvorscriften (Overhaul procedures).
I will continue in the next installment.

Cheers

SM

[schwarze-man]

The Instandsetzungsvorscriften (I will call this the Instand) is a large technical document that covers in detail the servicing and overhaul of the Motor. It describes the scope of the work that can be done "at the Front" (possibly unit based), the work for Teil-uberholung (at overhaul centres) and, the Grunduberholung (at the DB "Works"). Please note, the overhauling system may have differed in reality but the definition of the work and the level of the unit that could undertake the work is established.
The detail in the Instand is quite high. Interestingly, the scope of the Teiluberholung is quite considerable. Not surprisingly, the Grunduberholung includes all the Teiluberholung work and, gets the engine fully dismantled with the conrods removed, the crankshaft removed, the rear gearcase removed etc, and all dismantled for overhaul.
I do not wish to write all this out here, but, as an indication of the level of the Teiluberholung, it includes the cylinderblocks removed and pistons removed for examination.
So, the Instandsetzungsvorscriften is the complete "overhaul manual" that includes all normal DB servicing of the engine.
Some items, such as the Injection pump, are not covered to full dismantling or reconditioning because they are very specialised.
Overal, there is a lot of information in the Instand.
The next document is also very interesting, the Reparatur Anleitung DB 605 A-B and I will cover that next.

Cheers

SM

[schwarze-man]

Incidentally, For anyone interested in the DB605, I strongly recommend buying the CD of DB605 documents from Udo Hafner Archiv. For 59Euro it includes a large amount of technical documents that you can print, or watch on PC.
The compilation includes the documents, Handbuch, Instand and Reparatur Anleitung. To note, just the Instand is 263 odd pages. All docs are clear and all in German.

SM

[schwarze-man]

The first two documents above were originally Daimler-Benz publications of the Motor Handbuch and the Instandsetzungsvorscriften. Later, these were slightly modified and issued as the service documents D. (Luft) T. 3605 etc.
This next document seems to be a Daimler-Benz manual that was designed for repair and overhaul centres. This is the Reparatur Anleitung DB 605 A-B (Repair guide).
The previous Instand covers work to overhaul the engines within the normal wear and usage. The Reparatur Anleitung DB 605 A-B is designed for repair of damages beyond the normal wear and tear but, it also includes modifications and updates of the engine (of which there are a considerable number) and notes about recording engine overhauls. The Reparatur Anleitung DB 605 A-B comes in developing versions as the engine is developed, I have two versions, and there would have been more. However, this is not the end of the technical documentation for the DB 605 A. In Summer 1942 the newly introduced DB 605 was restricted to reduced power due to engine failures. These failures were mainly due to combinations of Exhaust valve metal problems, poor Injection Nozzle spray pattern, Lubrication weakness due to low oil flow and thin-crown Pistons. Operational instructions were issued and limitations imposed, then lifted when remedial work was completed. These improvements are seen in the later issues of the Reparatur Anleitung DB 605 A-B.
Before we move-on to consider the DB 605 A-B engine life, it is worth considering the overall Repair/Servicing situation. Engines often suffered damage or malfunction within the normal Military use. Engines that required repair at overhaul facilities would be assessed for the need to incorporate various updates and servicing. There would be little point in just repairing an engine with a burn't exhaust valve if it was say, half-way to a Teiluberholung.
There will have been guidelines on the management of engine repair/overhaul but, there is no guidance on that or, on engine life extensions as a policy in any of these documents. edit. *However, as of 4/11/22 I have seen RLM docs with airframe and engine life extension information and this will be covered in due course.*
Next, I am going to cover the servicing-cycle examples.

Cheers

SM

[schwarze-man]

Now, to illustrate a servicing record on the engine data record schildes that were used on some DB605 engines, I will first list the example given in the Reparatur Anleitung DB 605 A-B. The information is in a table that has ten columns , each of six spaces, in the upper section that is for the overhaul record. I will try list the info as blocks here in a similar layout.
Werke Nr 69010
T3552 G3652 T3651 G3652
...18.....78......12.......51..
..141...941...1241....542

So, those figures are four vertical columns of info, each column is one servicing event. I will leave this up for an hour and invite any quick replies, then I will go through the data.

Cheers

SM

[schwarze-man]

No takers? OK, fair enough this is not all straightforward.
So, first-off, the engine here, Werke Nr 69010 was a DB 601 E, you can tell from the engine database. Daimler-Benz have used this slightly earlier info but, it is still relevant as it had the same 200 hour Grunduberholung planned life with 100 hour Teiluberholung as the DB 605 A-1. However, this lifecycle was rarely achieved, as we can tell.
The horizontal lines of data are as follows:
Top line, is the type of overhaul Teil (T) or Grund (G) and the workshop code.
Middle line is the hours since previous overhaul.
Bottom line is the date of overhaul.
Therefore, this engine flew 18 hrs from new and had a Teiluberholung at Werke 3552 completed in Jan '41. The engine then flew 78 hrs before a Grunduberholung at Werke 3652 completed Sep '41. It then did just 12 hours before it's next T service, after which it managed 51 hours before a G service. The engine is now into it's next nominal 100 hours before another T service.
So, this information shows a great deal. Not least that the flight time between overhauls was very much lower than the nominal. This is not surprising, and it is likely that the reasons are damage, engine partial failure or management decisions to incorporate upgrades/modifications.
The lower section of the Schilde is for recording modifications and other work, recorded this time with: a code for the mod, the Werke and the date, again in a column of three blocks, eg 101-3652-842.
Overall, the "Life" of the Motor is consistently related to the Grunduberholung cycle, ie 100 hrs for a 0-series and 200 hrs for a 1-series, with a Teiluberholung at half that period. However, other combinations of engine build standard could limit these nominal life figures. For example, the previously noted problem with thin-crown pistons attracted a limit of 75 hrs and there were other combinations. It is interesting that the engine Schilde does not seem to carry the life limit for the next overhaul. It is presumed that information was recorded on the engine record.

Cheers

SM

[HGabor]

Hi folks,

A new number: DB 605A/1 engine, WNr. 25 552 was installed on Bf 109G-2 WNr. 13497.


Cheers,

Gabor

[schwarze-man]

Originally Posted by HGabor

Hi folks,

A new number: DB 605A/1 engine, WNr. 25 552 was installed on Bf 109G-2 WNr. 13497.


Cheers,

Gabor

Thanks for that Gabor!
Another part of the big story.

SM