"Good war for non-credible defense innit?" - Winston Churchill, probably.
Clockwise, starting from the top left:
Cluster bombs of 30,000 poisoned sewing needles:
Darts made from sewing needles and other materials, and containing a potent poison (possibly anthrax), were to be dropped over enemy targets by aircraft in specially designed cluster bombs.
The darts weight about 4 grams and when dropped from high altitude could penetrate two layers of clothing and human flesh, reportedly "for six inches until stopped by bone".
It was estimated that up to 30,000 needles could be packed into the cluster bombs.
Scientists of the infamous biological warfare site Porton Down were tasked with developing the poison for the darts.
The project was withdrawn in 1945.
- A diagram of the dart is shown above
The UP - unrotated projectile:
The original UP was a naval weapon consisting of a twenty tube rocket launcher.
The rockets were launched to a distance of about 300 meters, where they exploded and released an 8.4 oz (240 g) mine attached to three parachutes, by 120 meters of wire. An airplane hitting the wire would draw the mine towards itself, where it would detonate; thereby neutralizing the aircraft.
In one test aboard HMS Hood, the lines became entangled on the ship from shifting wind, causing damage.
It was withdrawn from service in 1941 because it was retarded.
Ironically, it closely resembles the later developed and credible, RIM-116 missile launcher.
Hafner Roatabuggy:
A Willys jeep combined with a rotor kit, designed to be towed behind an aircraft - a flying Willys jeep.
The introduction of towed glider aircraft led to the project being canceled.
Exploding rats:
Conceived in 1941, the British Special Operations Executive decided to slaughter 100 rats, and fill the carcasses with plastic explosives and a trigger mechanism.
The plan was to distributed the rat bombs near the boiler rooms of German factories and other important sites. They reasoned the rats would be found and thrown into the furnace, where they would detonate and in turn cause the boiler to explode.
The explosive rats never saw use because the first shipment of rat bombs was intercepted by the Germans. However, the Germans search for more booby-trapped rats consumed German resources, so the SOE decided their operation was a big success.
The Panjandrum (spinning cart of death):
A large rocket propelled two-wheel cart, packed with explosives.
It was designed to breach fortified defenses of the Nazis Atlantic Wall, and to be deployed from landing craft.
In theory, Panjandrum would quickly roll up the beach and crash into enemy defenses.
The project was canceled shortly after testing, as it proved to be inaccurate and dangerous to use - veering off course and targeting its owners.
Project Habbakuk:
The plan for an oversized mega aircraft carrier made out of pykrete (a mixture of wood pulp and ice). The carrier would operate in the mid-Atlantic, and conduct ASW (anti-submarine warfare) operations in the defense of Atlantic convoys. The project's name was originally a misspelling of the Biblical Habakkuk.
It was the brainchild of eccentric inventor Geoffrey Pyke - which pykrete is named after, although Pyke did not invent pykrete.
The project initially received approval, and was allegedly enthusiastically supported by Winston Churchill.
However, it was plagued by extensive cost overruns and an enormous effort in resources and time. The introduction of escorts carriers and longer range aircraft further rendered habbakuk as redundant.
The project was canceled in late 1943.
Have a looks at the Hobart's Funnies designs section:
https://en.m.wikipedia.org/wiki/Hobart%27s_Funnies