Re: Airfield Runways in Norway
 

Br/Goran -

I think something is wrong with the e-mail address you provided. I just received this:

Leveringen mislyktes til disse mottakerne eller distribusjonslistene:
mkff@luftnett.com
Finner ikke mottakerens e-postadresse i mottakerens e-postsystem. Microsoft Exchange vil ikke prøve å sende denne meldingen for deg på nytt. Kontroller e-postadressen og prøv å sende denne meldingen på nytt, eller send følgende diagnosetekst til systemansvarlig.

L.

Re: Airfield Runways in Norway
 

......believe it shall be kff@luftnett.com
Skip the "m" in the beginning.

Re: Airfield Runways in Norway
 

Thanks, Gladiator, I will give it another try.

L.

Re: Airfield Runways in Norway
 

Hi Larry. Iinteresting question and observations.

I may be able to add a few points.

While the translation are essentially correct it should be noted that "treseksjoner" does not refer to the wood sections inserted betwween concrete blocks (although they were there), but is more of a synonym of "plankedekke" in this contect.

Many Luftwaffe airfilelds in Norway were made in this way; first a concrete runway was laid down which was then covered by "treseksjoner" thus forming a "plankedekke"! Does that make sense?

Perhaps this seems odd to you, but there is now enough photogrpahic and anecdocal evidence to show that this was done. There is a collection of photos on the following website which shows what can be termed "treseksjoner" being made and prepared for placing down on what I believe is Forus airfield near Stavanger, sometime in 1941., but unfortunately the photosection of the webiste seems to be down. There are also several photos showing this being done at Herdla, but as I am at an airfield myself at the time of writing (with concrete runways only!) I don't have these available. I can post later if you are interested.

http://www.norgeslexi.com/krig.html

The reason for using wooden top deckings on the runway was partly because of the immense levels of rain, I think, and also because it would reduce damage in case of bombing and be cheap and easy to replace. It was not popular amongst pilots however, as can be expected, many pilots remember the distinctive sound made when taking off and landing and such runways tended to get very slippery when wet. There is a reason why there are so many photos of Luftwaffe aircraft on the beach at the end of Herdla's north-south runway, it is not just due to the short runway!

Perhaps Andreas Brekken and me should take our idea of making a series of books on Luftwaffe airfields in Norway during WWII beyond the talking stage???:-)

Best regards,

Kjetil

Re: Airfield Runways in Norway
 

Thank you very much, Kjetil, that's a wonderfully comprehensive answer and, I might add, an answer I was not expecting! I never would have thought of wood planking on top of concrete in a thousand years. It still does not make a lot of sense to me and I am not aware of Luftwaffe airfields being constructed with a wood cover over concrete elsewhere outside of Norway and probably Finland. There must have been some danger of blown tires from large, sharp wood splinters puncturing them during landing, I would think. I cannot help but suspect that there must have been some other reasoning involved besides rain drainage and protection for the concrete in case of air attack. If not, then it is strange that the Luftwaffe would not have used this method for other airfields in Europe where heavy rain and air attacks were a problem. There certainly was no shortage of wood and sawmills in the rest of Europe at that time so the raw materials (trees) and the means of production were available. This all comes as a strange surprise. I am enlightened yet still puzzled! :):confused::)

Larry

P.S. I am quite sure your book idea would be welcomed by many!

Re: Airfield Runways in Norway
 

Hi,
I have followed this discussion with some interest, and I am surprised at the answer as well. German runways in Denmark had a distinctive slope from the centerline to both sides (crown ?) and there was a gutter along the entire length of the runway. This was connected to a very effective drainage system, at Aalb-West even augmented with pumps (which incidentally are still hard at work). But I can offer no alternate explanation to wooden planks on top of a concrete runway.
I for one would also welcome a book on German airfields in Norway, but if I remember correctly concrete is not one of your favorite topics Kjetil ;).
bregds
SES

Re: Airfield Runways in Norway
 

Not unless it has castings of arachnids! ;)

Re: Airfield Runways in Norway
 

There are many different concrete mixes varying with the ratio of the fine aggregate, coarse aggregate and cemant used and also with the cement/water ratio in the mix. It would be interesting to know the specification of the concrete mix used. Were the runways constructed with a strong reinforced mix or with a leanmix (low cement content). The leanmix type would tend not to break its back if subject to ground movement due to wet/clay type conditions which are subject to a large temperature variation. But would tend to undulate with ground movement. Was the concrete laid some 150mm below ground level and then the runway bought back to ground level with the timber decking, this would have given the concrete some protection from the elements and provided good surface drainage. If a leanmix type was used this would have minmum curing time before use, as opposed to the use of a stronger reiforced type of concrete needing 28days+. If a runway had to go down fast a leanmix type with a timber decking could be constructed much faster than a traditional reinforced concrete one.

Re: Airfield Runways in Norway
 

You must be a contractor or a retired contractor, Brian. You know your stuff about concrete.

I want to go with lean mix because the runway construction season in central and north Norway was mid-May to the end of September and a bit longer than that in south Norway. The concrete runways were in some cases constructed by Lw.-Bau-Btle. using Norwegian civilian labor, Norwegian political prisoners, Russian POWs, etc., and in other cases by the Organisation Todt with the same variety of labor. Some of the concrete runways were put down in a single season while others were under construction for 2 and 3 years before they were completed. Some were even started in 1940-41, abandoned from 1941-44, and then restarted and completed by the end of the war.

Coastal ships carrying timber from sawmills in the Trondheim area were continually sailing back and forth to ports serving the airfields in northern Norway, and some also had steel matting listed on their manifests, at least that's how Bletchley Park translated it.

So it looks like your strong reinforced mix was used in some cases and your lean mix in others. But your thoughts on how the treseksjoner sections might have been used in conjunction with a lean mix runway are very interesting.

The airfields north of Trondheim (Bardufoss, Banak, Alta, Kirkenes and some others) had a permafrost problem that plays into the drainage issue because it would have been quite difficult and time consuming to dig down below the peat outer layer and penetrate the permafrost to lay any kind of a foundation for the concrete that was deeper than a few inches. Unlike the others, Kirkenes had gravel runways which the Luftwaffe bomber guys hated because the He 111s and Ju 88s could not use Kirkenes to fly torpedo strikes. The gravel would kick up and damage the torpedos.

L.

Re: Airfield Runways in Norway
 

Larry, Alas now retired, I worked in the construction industry and later for local authorities on Highway Maintenance. Practical side not on the design side. Its only my thoughts Larry I would have thought these runways would have to go down pretty quick and could not see the reason for bringing a concrete runway to ground level then putting a decking on top. However we live and learn, it would be interesting to see if this type of runway construction was unique to Norway,

Regards

Brian Bines