JamesFennell MBE Profile picture
Dec 30, 2025 99 tweets 36 min read
Convoys from South Africa, India, Australia and South America to the UK formed up in Freetown's vast natural harbour before proceeding under escort to Gibraltar and Britain. These Defiant target-tugs were used to drill the merchantmen in anti aricraft fire before they departed. Sloops carried out day-to-day flag waving and policing duties from all of the major colonial ports, and from 1916 had been built with a secondary capability for use as convoy escorts. This included the fitting of depth charge racks and the earliest form of sonar - ASDIC. Image
Dec 27, 2025 4 tweets 2 min read
Britain is buying Sky Sentinel AI controlled C-UAS turrets for Ukraine. These Ukrainian systems use EW and a 12.7mm Browning M2 HMG and are extremely effective against subsonic drones like Shahed. 10-30 of the $150K turrets are needed to protect a city. militarnyi.com/en/news/sky-se… Sky Sentinel uses 'foreign components' which suggests a UK-UKR collaboration in design and manufacture. AI controlled, they do not require indivdual operatators, but can be integrated with and operated as part of an IAMD systems from remote command posts. Image
Dec 25, 2025 27 tweets 11 min read
A thread on rapid scaling of the Royal Navy using quick-build autonomous systems:

1SL Gen Gwyn Jenkins has endorsed this approach, following his 'uncrewed where possible' mantra, but understanding that uncrewed will augment rather than replace crewed capabilities. Image This means building low-cost, attritibel uncrewed systems to the current technology levels, rather than high-risk bleeding edge capabilities. So using proven remote control and AI autonomy on fast-build platforms for escort, ISR, picket dury/outer layers and magazine depth. Image
Dec 19, 2025 18 tweets 7 min read
The STEN.

In 1940 Britain only porduced the heavy and complex Lanchester SMG, a copy of the 1920s German MP28. The Lanchester was designed for use by naval boarding parties and also issued to the the RAF Regiment. It was made of high quailty materials and expensive to produce. Image Large numbers of Thompson SMGs were ordered from the United States in 1939, but supply could never meet demand, especially after the US entered the war in 1941. The Thompson was also expensive to produce and relatively complex. Image
Dec 11, 2025 22 tweets 8 min read
Lets look at the Second Tactical Air Force (2 TAF) and how RAF air support for 21st Army Group was organised and delivered.

2TAF was built on lessons in close air support learned in the Mediterranean with the Desert Air Force (later renamed the First Tactical Air Force). Image Formed in July 1943, command passed to Arthur Coningham in January 1944, the New Zelander who had led the Desert Air Force from 1941-43 and pioneered the use of forward air control, 'cab ranks' and the rapid construction of forward air strips behind advancing ground forces. Image
Dec 10, 2025 15 tweets 5 min read
New drone production facilities in the UK.

A quick thread noting some of the new capacity unveilled this year.

1./ Ukrspecsystems, the Ukrainian drone producer opened a new $250 million factory at RAF Mildenhall in Suffolk, as well as test facilities at the airfield. Image UKrspecsystems manufactures the PD-2, Shark and mini-Shark ISR UAVs. Shark is likely to be built in the UK for both Ukriane and the British armed forces. Image
Dec 4, 2025 10 tweets 4 min read
Lets look at the P-51 as an exercise in getting the right kit to the guys quickly.
1./ NA took a risk - they could have made $$ building P-40s, but they wanted more.
2./ They adopted the latest tech - they used NACA's secret R&D sauce to make the P-51 super slippery. Image ... more slippery than the Bf 109, the Spitfire or the FW 190.
3./ NA were aided by a tight Air Ministry specification, designed around real combat experience against the Luftwaffe.
4./ The engineers were left to get on with it - no SRO changing the specs, 90 days is all it took. Image
Nov 22, 2025 14 tweets 5 min read
Fascism is difficult to pin down, we use it as a shorthand for evil, but it was rooted in time. Especially the humilitiation of defeat during WW1, and the desire to overturn Christian ideas of universal human dignity in favour of ethnic supremacy in the cause of national renewal. Image At its heart is the repudiation of the Christian idea of the universal human condition which underpinned European enlightenment culture. So in a strange way it looked back to pagan myth but in the service of a building a new world, one which rejected the 'brotherhood of man'. Image
Nov 20, 2025 8 tweets 3 min read
In 1939 the FAA and RAF's anti-shipping options were at best antiquated. Both were equipped with obsolete slow-flying biplane torpedo bombers.

The navy also had a small number of more up to date monoplane dive bombers, procured by claiming they were fighters. Image The modern Mark XII and XIV 18" air launched torpedo were entering service to replace the fragile Mark XI (most of which were repurposed for use by MTBs), but the armour piercing bomb dated from the 1920s had a tiny explosive charge and couldn't be carried by Skua dive bombers. Image
Nov 5, 2025 21 tweets 8 min read
Generating mass. The Sherman Tank.

The American strategy in WW2 was to find ways to produce more of a 'good enough' tank design than the opposition - the M4 Sherman. Different variants largely reflected ways of increasing production rather than enhancements in design. Image The M4 was initially designed to be built by locomotive manufacturers using a fully cast hull and turret. Casting saved time and required fewer skilled employees to build than welded fabrication. The baseline M4 was powered by a modified Wright Whirlwind 1920s aeroengine. Image
Oct 22, 2025 16 tweets 6 min read
Getting things done in Britain:

How Sgt. Rod Banks and the Mosquito shadow modification network gave Mosquitos the extra ooph to avoid Luftwaffe fighters.

Rod Banks was a lowly engine fitter at RAF Marham, exceptional engineer and former Rolls Royce apprentice. Image When the Mosquito entered service it was very fast at 380mph at altitude, but soon pilots found that the new Bf 109G and Fw 190A fighters could catch them.

Banks had realised there was a small discrepacy between the tolerances of the engine and the the meximum boost limit. Image
Oct 21, 2025 29 tweets 10 min read
On Trafalgar Day its worth looking at the post-1840 reforms that turned Britian's then often defeated navy into the precision instrument of victory wielded by Nelson and Pellew in the Napoleonic Wars. Many have resonance to this day. Image The key moment was the appointment of John Montagu, 4th Earl of Sandwich, as First Lord of the Admiralty from 1747-51, 1763 and 1771-83. He oversaw a series of far reaching naval reforms and also invented fast food, both of which came to define the Anglo-Saxon world. Image
Oct 9, 2025 9 tweets 2 min read
Carl Schmitt's 'state of exception' being engineered in America. Schmitt, a jurist and philosopher (and later a Nazi party member), introduced the idea of the 'state of emergency' in his 1921 essay 'on dictatorship' as a concept to enable a strong executive power to overrule the Weimar constitution. The Italian philosopher Georgio Agamben developed this further in his 2005 book 'state of exception' to show how this could be extended indefinately.

Schmitt helped draft legislation after the Reichstag Fire to temporarily suspend civil liberties which was never repealed.
Oct 4, 2025 24 tweets 9 min read
Second lives.

Many obsolete aircraft had second lives on D-Day. 12 new Hurricane IIc were modified to carry 31 cu ft.mail by 1649 (Air Dispatch Letter Service) flight from RAF Northolt. Working with the Post Office they delivered mail to US and UK forward airstrips in France. Image Mail was carried in the port droptank and in the fuselage aft of the pilot. Guns were retained but no ammo was carried to reduce weight. By this time Hurricane production was ending, but they were still used by training units. Image
Sep 30, 2025 32 tweets 12 min read
The A22 Churchill infantry tank - an unlikely success story.

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The Churchill failed, failed and failed again, and yet evolved into the most useful British tank on the 1944-5 battlefield. Image The Churchill has its origins in hastily dusted off plans to send a new BEF to France after the Munich crisis in 1938.

Envisaging a return to 1914-18 trench warfare, the War Office issued a requirement for a larger gap-crossing infantry tank to complement the Matilda. Image
Sep 10, 2025 17 tweets 6 min read
1SL Gen Gwyn Jenkins set out an ambitious strategy for rebuilding the Royal Navy yesterday:

1⃣ within 100 days a plan to deliver full capability in 4 years and new assessment methods trialled to select a new cadre of wartime commanders.
gov.uk/government/spe… 2⃣ mass to be generated by rapidly delivering uncrewed systems to team with crewed ships, submarines and aircraft. The first LUSVs and collaborative combat aircraft to be inducted in 2026.
3⃣ largest maritime warfighting training overhaul since the Cold War. Image
Aug 30, 2025 7 tweets 3 min read
The UK's plan to aquire 7,000 long range weapons is becoming clearer. In addition to the FC/ASW 1,000km TP15 and RJ10 subsonic stealth and supersonic cruise missiles for the RAF and RN, the Army will deploy 600km BRAKESTOP OWEs and NIGHTFALL tactical ballistic missiles. Image Both BRAKESTOP and NIGHTFALL are sovereign developed, ITAR-free and domestically produced capabilities, like FC/ASW, but unlike the Anglo-French-Italian MBDA missile programme and to be low cost and rapidly developed for fielding before 2030. Image
Aug 23, 2025 34 tweets 12 min read
Lets talk about castles.

The castle was a Norman military innovation of the 11th century. It enabled a small elite, highly mobile military force to dominate and control large territories and much larger populations. The castle served as an impregable command post, observation post, supply dump and garrison for a highly trained raiding force of mobile (mounted) warriors. These became 'knights'. The Normans, of Viking descent, used them to wrest control of territory in northern France. Image
Aug 9, 2025 23 tweets 8 min read
By the 1980s the fleet had settled at 50 FF/DDs, of which half were 1970/80s Type 21/42/22 and half upgraded 1960s Leanders, Counties and Type 12s. The first Type 23 (Leander replacement) was comissioned in 1989. Image All were active, and the 1970s ships considerably larger at 4,000 to 4,500 tons). Three VSTOL carriers were built in the '70s and early '80s and a total of 56 SHAR aquired, enabling a more limited carrier strike capability to be regenerated. Image
Jul 11, 2025 11 tweets 4 min read
IAMD priorities
- Portsmouth, Faslane, Devonport, Gibraltar naval bases
- Lossiemouth, Coningsby, Marham, Brize Norton, Akrotiri RAF bases
- GCHQ Cheltenham, Whitehall, Wyton, Waddington C2, ISR.
- Fylingdales and 8 Remote Radar Heads
- AWE Aldermaston and 6 nuclear power plants. Image On the 'The Wargame' Sky podcast, Gen. Sir Richard Barrons, one of the SDR architects, said an 'Iron Dome' for the UK would cost £24 billion and is thus unaffordable.

Nevertheless, we should explore cheaper and more flexible means of providing IAMD against a first strike. Image
Jun 30, 2025 15 tweets 5 min read
In the 1930s the RAF allocated '300' series squadron numbers for crews from occupied nations and the '400' series for Article XV squadrons crewed by commonwealth allies.

Numbers 1-299 were regular RAF, 500 series for the Special Reserve and 600 for the Volunteer Reserve. The first 300 series squadrons were formed in July 1940 with experienced Polish refugee aircrews.

Four (300, 301, 304 and 305) were bomber squadrons, initially given Fairey Battles withdrawn from RAF service, which were exchanged for Vickers Wellingtons by the end of the year. Image