Care and Maintenance of Grass Airfields

[Conslaw]

They used a lot of grass airfields in WWII, especially in England. How did they maintain them? What kind of mower did they use? How high was the grass?

What makes me think of this is the football season, where even immaculately kept football fields can get pretty ragged once the weather gets too cold for the grass to grow. Were the grass fields in England 4-season capable?

Switching over to the Pacific. I guess Fighter 1 and Fighter 2 were grass fields that were established on a ridge where there had been high kunai grass. Did they just cut the kunai grass, or did they put in other grass?

 

[gumbyk]

Not too sure about England, but Marston Matting was used extensively in the Pacific. A lot of the airfields were also a coral base, which didn't turn to mud, and was well drained.

 

[SaparotRob]

Did they have a problem with coral dust?

 

[nuuumannn]

Did they have a problem with coral dust?

Yes! Coral dust eats aluminium. I've seen the results of erosion on aircraft from frequent use on coral runways. It's not pretty. A company I used to work for did the heavy maintenance checks on Air Rarotonga's Saab 340 and it was a mess every time. In a prop shop I used to work for, we overhauled Air Raro's Bandit props and the blades were rubbish and had to be replaced each time, exceeding tolerances on every check. Scurfing wasn't going to cure those blades, they were Swiss cheese.

 

[SaparotRob]

Was the Saab's home field using improved runways and that was just from dust blowing around or they still using strips from WW 2?

 

[pbehn]

You aint seen nuttin, this is a chewed up pitch, from the notorious Derby County Baseball ground (we used to play a lot of baseball)

Early in the war fields were grass but quickly switched to concrete/ asphalt or metal matting. There were 60,000 people employed in building airfields, equal to a highway from UK to China.

 

[nuuumannn]

Was the Saab's home field using improved runways and that was just from dust blowing around or they still using strips from WW 2?

Air Raro's main base is Rarotonga's airport, which is a big concrete strip capable of handling aircraft up to 747 size, but the smaller islands in the Cook Islands have coral strips, some of them built in WW2.

Raro airport with one of Air Raro's Bandits on the pan.

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Dreamliner crossing the fence. Great spot for photography.

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Aitutaki International Airport, as it calls itself has a concrete strip, but it's not a big runway. You could probably get a 737 in there. Air Raro's Saab at Aitutaki.

Aitutaki 01

Aitutaki's old coral runway built by the New Zealand Public Works Department, which sent workers throughout the Pacific islands to construct airfields during the war.

Aitutaki 04

 

[pbehn]

There was one aircraft, I think the BP Defiant, that had its undercarriage modified because the spats were catching on the grass, so the grass height was below the wheel axles.

 

[nuuumannn]

The Defiant did have undercarriage issues to start with, which meant that BP went to a different supplier, but it wasn't because of the length of grass. The Dowty gear sometimes failed to lock into position and Lockheed provided an engine driven pump to actuate the hydraulics, and the Dowty shock absorbers were replaced by Lockheed ones. Originally the lower gear doors had a semi circular flap that folded sideways on the lower covers, but this was removed from that location (possibly because of grass) and were replaced with doors on the aircraft centreline instead to enclose the undercarriage completely when in flight. This all happened on the prototype, so the production aircraft didn't have these issues. The Defiant did have a brush mounted to the undercarriage leg that brushed mud off the wheels when they retracted.

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[SaparotRob]

I never knew that. The Defiant really is a beautifully put together plane. No wonder there are so many "what if" Defiants out there.

 

[nuuumannn]

The Defiant really is a beautifully put together plane.

I agree, I got the opportunity to get a good look at the survivor at Cosford the last time I was in the UK. It's a pity is has such a bad reputation today, it really was a masterfully designed machine.

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[Conslaw]

Here is a Spitfire with an "oops" on a grass field.

 

[elbmc1969]

Trying to remember ... one the French aircraft had a terrible problem with the gear throwing rocks into the empennage? Radiators? Fuselage? I forget, but it was a serious problem.

 

[EwenS]

While it might seem simple, creating a grass airfield in Britain was a complicated process to ensure a workable airfield.

Site selection - preferably an area with a convex contour to minimise drainage requirements. Right soil type. Access and amenities also taken into account.
Site clearance - hedge removal, ditch filling, timber removal etc. (agricultural field sizes then were much smaller than today or in the US even then)
Removal of hillocks and depressions with machinery
Consolidation of landing areas with roller
Light ploughing to 6"
Selection of grass mixes to be sown taking account of site, weather conditions and soil conditions.
New grass was then cut at 4"
Field drainage would have to be installed to suit the site and to ensure it could be used all year round.

The test for smoothness of the finished article was a sophisticated comfort test of driving a car across it at 20mph!

Grass fields were fine until aircraft weights began to increase from the late 1930s. Then added to that was the much increased usage of wartime which began to cause problems with surfaces becoming cut up in winter causing undercarriage collapses.

1938 saw the first hard runways installed at Odiham & Gosport which were particularly wet as grass strips. By the end of that year hard runways were seen as essential in light of increasing aircraft weights and work began on 8 fighter airfields in 1939 and then on existing bomber strips by the end of 1940. But it took some time to ensure all existing airfields got them. Training fields came further down the priority list. Often a starting point was a hard perimeter track.

In 1944, in the run up to D-Day a significant number of temporary airfields were required in southern England to forward base many of the fighter squadrons needed to support the landings. These used PSP or Marston Matting.

I'd recommend Robin Higham's "Bases of Air Strategy - Building Airfields for the RAF 1914-1945" for a review of the whole process of airfield building. This covers not only the U.K. but all the theatres of war where British forces required airfields.

And then add to that the separate question of airfield buildings, from control towers to hangars to accommodation blocks and specialist training buildings. For those see
Paul Francis "British Military Airfield Architecture - From Airships to the Jet Age"

 

[nuuumannn]

1938 saw the first hard runways installed at Odiham & Gosport which were particularly wet as grass strips. By the end of that year hard runways were seen as essential in light of increasing aircraft weights and work began on 8 fighter airfields in 1939 and then on existing bomber strips by the end of 1940. But it took some time to ensure all existing airfields got them. Training fields came further down the priority list. Often a starting point was a hard perimeter track.

Good info, Ewen. All things considered, the effort the British put into building concrete runways was huge, not least because of the sheer volume of work that went into the task between 1939 and 1941/2, the number of new airfields the British built in such a short space was staggering.

Training airfields certainly did get attention, standardising on existing airfield layouts - the Type A (Bomber) Dispersed Airfield layout of three runways in a triangular cross pattern became a staple around the country. This is RAF East Fortune in Scotland, on which work began in late 1940 and opened in 1941 as a night fighter training station, with 60 OTU on Defiants, but in 1942 (when this image was taken) came under Coastal Command use and saw Beauforts, Beaufighters and Mosquitoes resident with 132 OTU. Note that there has been some attempt to camouflage the runways.

EF1942

Note the hardstanding at lower right with the domed hangar, situated above the cluster of buildings at the lower edge of the image, these hard sections were the bases of airship sheds during the Great War and still existed until the 1980s. Most of the infrastructure at bottom was constructed during the Great War in support of the airships.

 

[pinehilljoe]

A friend of mine had a grass field on his property for his private planes. It was well drained ground, with good sod. He had an old road roller, I forget if it was a Bomag or Ferguson to keep the field flat. Sad ending though, he passed when one of his planes engine quite just after take off, and he dove into the ground.

 

[EwenS]

Good info, Ewen. All things considered, the effort the British put into building concrete runways was huge, not least because of the sheer volume of work that went into the task between 1939 and 1941/2, the number of new airfields the British built in such a short space was staggering.

Training airfields certainly did get attention, standardising on existing airfield layouts - the Type A (Bomber) Dispersed Airfield layout of three runways in a triangular cross pattern became a staple around the country. This is RAF East Fortune in Scotland, on which work began in late 1940 and opened in 1941 as a night fighter training station, with 60 OTU on Defiants, but in 1942 (when this image was taken) came under Coastal Command use and saw Beauforts, Beaufighters and Mosquitoes resident with 132 OTU. Note that there has been some attempt to camouflage the runways.

View attachment 651697EF1942

Note the hardstanding at lower right with the domed hangar, situated above the cluster of buildings at the lower edge of the image, these hard sections were the bases of airship sheds during the Great War and still existed until the 1980s. Most of the infrastructure at bottom was constructed during the Great War in support of the airships.

I know East Fortune quite well. Photo is taken looking south. The three hangars at the top right now form the National Museum of Flight complete with a Concorde exhibit (in a new hangar just inside the peri track from the other three). Well worth a visit.

East Fortune is one of a cluster of former airfields in the area including Drem, used as a fighter airfield in the early days of the war, and passed to the RN in 1945 to train night fighter pilots. It never got hard runways but the perimeter track and some buildings can still be seen. Also Macmerry which did get hard runways which have now disappeared under an industrial estate. Some of its protective pillboxes can still be seen in the area.

 

[nuuumannn]

I know East Fortune quite well. Photo is taken looking south. The three hangars at the top right now form the National Museum of Flight complete with a Concorde exhibit (in a new hangar just inside the peri track from the other three). Well worth a visit.

As do I. I worked at East Fortune for nearly 8 years. I used to catch the train from Edinburgh each day and cycle from Drem station to the museum. I lived in North Berwick and Longniddry for a time during my sojourn in the region.

Pictures from my last visit a few years ago:

Scotland's National Museum of Flight

East Fortune, East Lothian, Scotland, 2018.

www.flickr.com

 

[Peter Gunn]

After WWII dad and his brothers turned the family farm into a grass airfield. As a kid I used to help out a lot there, as I recall, they had a deal with a construction company to roll the runways about once a year. They also were the local John Deere dealership so they had those huge industrial sized mowers on hand which as memory served, they kept the grass pretty close cropped.

Looks to no longer be a working airfield, although the wind sock is still evident, the east/west runway was disabled years ago, but you can still see the north/south in existence, or at least still kept as grass.

The green circle is the house I grew up in. The red X is where a Cessna 150 and I had a disagreement about landing procedures. The long hangar to the right of the X is the first one they built back in the '40's so at least it's still there.

 

[Snautzer01]

Airfield No 2 Servicing RAF ODIHAM 6 Sept 1943

WW2 -123 Airfield No 2 Servicing RAF ODIHAM 6 Sept 1943 | eBay

WW2 -123 Airfield No 2 Servicing RAF ODIHAM. 6 Sept 1943. A really valuable archive.

www.ebay.com