Report - - "Highball" WW2 Bouncing Bomb, Ashley Walk, Hampshire - March 2020 | Military Sites | 28DaysLater.co.uk

Report - "Highball" WW2 Bouncing Bomb, Ashley Walk, Hampshire - March 2020

Bertie Bollockbrains

There is no pain
Regular User
Obviously the Government's stay-at-home message remains, but I had legitimate reason to drive to Hampshire recently and took the opportunity to get to the former Ashley Walk Bombing Range which was only a couple of miles off my route. My aim was to locate the remains of a WW2 bouncing bomb.

Highball was one of two bouncing bombs developed by the brilliant engineer Barnes Wallis during World War Two.

Highball was designed to be used by Mosquito aircraft of the Royal Navy's Fleet Air Arm for use against shipping. It was hoped to had been used in the late spring of 1943 to attack and sink the German battleship Tirpitz which was known to be moored in a fjord in Norway.

Highball was developed concurrently with Barnes Wallis's other bouncing bomb "Upkeep", the much larger bouncing bomb that was carried by the modified Avro Lancasters of 617 Squadron RAF and designed for breaching dams.

Upkeep became operationally ready before Highball. As it was felt that the use of Upkeep on German dams would had compromised the secrecy and efficiency of Highball, the Royal Navy pressurised the RAF to delay Operation Chastice (The Dambusters Mission) until Highball was ready. It was felt that an assault by the Fleet Air Arm againist the battleship Tirpitz and an assault by the RAF on the German dams of the Ruhr should be conducted simultaneously. Alas the Dambusters misison was time critical as it would only had been successful with high water in the German reservoirs and thus delay into the summer months was not possible. Thus the Royal Navy had to give up on using Highball operationally and 617 Squadron RAF's Operation Chastice went ahead during the night of 16/17th May 1943 breaching the Möhne and the Edersee dams.

The German battleship Tirpitz was eventually sunk by RAF Lancasters in November 1944, ironically using "Tallboy" large-capacity bombs also designed by Barnes Wallis.

Ashley Walk Bombing Range
At the outbreak of World War Two a 5000 acre bombing range was built in the New Forest under the control of the Aeroplane and Armament Experimental Establishment at RAF Boscombe Down in Wiltshire, whose operating personnel were billeted in huts opposite the Fighting Cocks pub in Godshill. Whilst there were many other ranges established throughout the UK during this time, the range at Ashley Walk was unique in that it existed predominantly to test weapons, rather than for the training of bomber crews.

The range was divided into two separate parts. The first consisted of a 2000 yard diameter practice range used exclusively for dropping inert bombs that was controlled from a tower at Hampton Ridge, that was known as the Main Practice Tower. The second was the High Explosive Range that was controlled from the North Tower located close to the Fordingbridge - Cadnam road, and was much larger at 4000 yards diameter for obvious reasons. Both these locations contained a multitude of different targets, including several different air to ground targets, at least three wall targets, fragmentation targets, a ship target, and a so called submarine pen that was in reality a huge public air raid shelter, built by the Ministry of Home Security (responsible for civil defence).

Between 1940 and 1946 every type of air dropped ordnance used by the RAF (with the exception of incendiary weapons) was tested here, ranging from the small anti-personnel type bombs, to the ultimate in air dropped ordnance - the Barnes Wallis designed 12000lb Tallboy bomb, and the 22000lbs earthquake bomb, the Grand Slam. Only one live Grand Slam bomb was ever tested on UK soil, and this took place over the Ashley Walk range on the 13th March 1945 when a specially modified Lancaster flying at 16000 feet, released the bomb. Travelling close to the speed of sound it impacted about 80 yards from the Ministry of Home Security target, burying itself into the ground. After a delay of nine seconds, it exploded, creating a crater 130 feet across, and 70 feet deep To this day it remains the largest live bomb ever dropped on UK soil. This crater was later filled in.

Today, very little remains apart from the many bomb craters, a number of chalk target markings, and the concrete foundations of various structures.

Remains of Highball Bouncing Bomb
The "Highball" bouncing bomb carried by modified de Havilland Mosquitoes was a smaller version of the "Upkeep" bouncing bomb used in the Dambusters Raid in May 1943, and was intended to be used against shipping. It was never used in action. The inert versions tested at Ashley Walk were 35 inch spheres containing a cylinder filled with concrete that acted as ballast. These would often shatter on impact, and some of the ballast released survives in small dumps. This collection clearly shows spherical segments of some of the ballast the bombs contained.

You Tube video of a Bouncing Bomb test at Ashley Walk in April 1943 at this link

Observation Shelter
The most tangible relic that exists on the range today is this brick-built observation shelter at Ashley Cross, built in order to observe activity in safety at the nearby C & D fragmentation target at Coopers Hill.

A and B Fragmentation Target
Two sites on the range were specifically for testing fragmentation bombs, and designated A&B, and C&D respectively. The A&B site is located near to Alderhill Bottom. A number of aircraft pens were built here to test dispersal areas and their protection from fragmentation bombs, half of them built to designs used by the Luftwaffe. On the ground could be seen a large circle, I assume to indicate the target area. Nearby were bomb craters and rusted pieces of bomb fragment.

C and D Fragmentation Target
The second of two separate fragmentation target zones on the range, this one is at Coopers Hill. It was used to test fragmentation bombs and their effects against artillery and on troops. For the latter, wooden dummies were used in conjunction with wooden boards positioned to collect the bomb fragments. The photo shows the circular chalk outline denoting target centre between the C&D zones. The designation letters of "C" and "D" are still visible from the air but difficult to make out on the ground.

Live Bombing Range
In the centre of the live bombing range was a 200 yard diameter concrete apron that was used to test the effect of different types of bomb casings. The concrete was removed in 1991 leaving a large circular gravel area. Surrounding this were numerous bomb craters, many water filled...

Tallboy Bomb Crater
This popular watering hole for the indigenous New Forest ponies is actually a 12000 pounder Tallboy bomb crater. This bomb was among those designed by the genius engineer-inventor Barnes Wallis, and was first tested here at Ashley Walk before being successfully deployed during 1944 onwards against heavily fortified German bunkers, the German battleship Tirpitz and U boat pens.

Ministry of Home Security Target
Known also by its more popular name of Sub Pens, it was long thought the concrete structure underneath the mound was built to resemble a U-boat submarine pen. In reality, the ministry responsible for national civil defence - primarily air raid defence, was tasked with building a full sized bomb resistant public air raid shelter in order to test its performance. It consisted of a massive slab of concrete 6 ft thick, by 79 ft by 70 ft, and supported on five 6 ft high walls on foundations 20 inches thick. The outer walls were over 3 ft thick, the inner walls were 1' 9". It was completed in September 1941 at a cost of £250,000. This target was thus officially designated the Ministry of Home Security Target, after the ministry who built it. It proved to be indestructable, and after the war it was simply covered over with earth, and so it remains to this day, with sections of concrete showing through in parts where the soil has eroded.

Chalk Target
Remains of a heap of chalk that was used in the creation of targets and target markers.

Thanks for reading
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• Chief Noob Wrangler •
Regular User
Extensive report there Bertie and a very interesting read! Nice job!


Stay Safe

In April 1942, Wallis himself had described his proposed weapon as "essentially a weapon for the Fleet Air Arm". This naval aspect was later to be pressed by a minute issued by British prime minister Winston Churchill, in February 1943, asking "Have you given up all plans for doing anything to Tirpitz while she is in Trondheim? ... It is a terrible thing that this prize should be waiting and no one be able to think of a way of winning it." However, Highball was ultimately developed as an RAF weapon for use against various targets, including Tirpitz but was never used operationally.

Bertie Bollockbrains

There is no pain
Regular User
If there is one thing that amazes me most about the bouncing bomb/Op Chastice/Mohne Dam story it is that Barnes Wallis conceived and designed the bouncing bomb in his own spare time without approval from his employers - at the time he was employed full time as an engineer for Vickers-Armstrong aviation working on the proposed 6-engined Victory heavy bomber (a project that never reached conclusion by the way). The man truely was an genius and I am in awe.

Bikin Glynn

28DL Regular User
Regular User
Thats really interesting, have watched the vid before its pretty impressive & the guys standing watching :D


28DL Full Member
28DL Full Member
Fascinating bit of history there, especially the ballast bombs, I'm amazed they survived the impact let alone the 80 odd years or exposure since then

Calamity Jane

i see beauty in the unloved, places & things
Regular User
Amazing write up. I love the history and photos gone into this report. The fact that Barnes Wallis designed & created this in his spare time is mind blowing. That's commitment.


28DL Member
28DL Member
If there is one thing that amazes me most about the bouncing bomb/Op Chastice/Mohne Dam story it is that Barnes Wallis conceived and designed the bouncing bomb in his own spare time without approval from his employers - at the time he was employed full time as an engineer for Vickers-Armstrong aviation working on the proposed 6-engined Victory heavy bomber (a project that never reached conclusion by the way). The man truely was an genius and I am in awe.
Hi, there were and still are many dedicated geniuses who do this. It's not nor ever was uncommon, it just wasn't meant to be released because they do not like us to know the truth. My grandad who was in both Local Government Civil Service and the RAF from the interwar period then active service in the Shetland Islands, Trinidad and Tobago then India and Burma and didn't get demobbed until late 1946 then back to Bournemouth Municipal Corporation Education Dept. He died in 1976 & I have no living memory of him. His second wife, a lady he'd met during his WW2 service was a WAAF and is still alive at nigh on 100 years old, bless her. However this means that the only information on my grandad and his RAF service I'm allowed from The War Office is Substantive Services. Which is Spook Services, Reconnaissance, etc and his own mother was related to an inventrix called Arabella Hurdle who patented design technology for new prambulators springs for babies walking prams aside other brainwaves of genius. That's why gifted people whether Arts, Sports or Science are hunted down and contracted by the MILITARY INDUSTRIAL COMPLEX, because those who destroy cannot create and contracts can rarely be unsigned or undone. You will not ever know how many people like me and my family have experienced having a branch of an agency of something appear miraculously to offer assistance then all the plans, models, macquettes and everything "Borrowed for testing" never sees the light of day again. This is why I do art not war. Remember what they did to Alan Turing.