The first battle of Gallipoli was fought from 19 February 1915 to 9 January 1916. The Entente powers (Britain, France and the Russian Empire) wanted to weaken the Ottoman Empire by taking control of the Ottoman straits. This would expose the Ottoman capital of Constantinople to bombardment by Entente battleships and cut it off from the Asian part of the empire.
In February 1915 the Entente fleet failed when it tried to force a passage through the Dardanelles. The naval action was followed by an amphibious landing on the Gallipoli peninsula in April 1915. In January 1916, after eight months' fighting, with approximately 250,000 casualties on each side, the land campaign was abandoned and the invasion force was withdrawn.
The Gallipoli objective was still seen as strategically important, and after this very public defeat, Winston Churchill was determined to salvage his reputation as a strategist and leader. In order to do this, he got together with  General Hunter-Weston and formulated a new plan of attack in order to seize the Dardanelles, taking seriously into account the lessons learnt from the first campaign such as how it was plagued by ill-defined goals, poor planning, insufficient artillery, inexperienced troops, inaccurate maps, poor intelligence, overconfidence, inadequate equipment, supply and tactical deficiencies.
After the failure of the first campaign, a revolutionary new weapon had been created that would change how land battles would be fought. The tank.
Churchill thought this could be one of the deciding factors of being able to solidify the Entente's position on a beach head, take out the troublesome Ottoman artillery and advance inland where conventional warfare could then be fought.
The issue that the planning team could not solve was how to bring the tanks ashore. Any boat with a shallow enough draft wasn't large enough to support the weight of the British heavy tanks. Sir Douglas Haig then suggested that the tanks could be modified to become "amphibious". The idea was initially met with raucous laughter until Sir Haig sketched his proposals based on the latest heavy Mark.IV on the back of a bank cheque.
A bus building firm based in Liverpool was contracted to make the modifications to Mark.iii training tanks as proof of concept. There were two types of amphibious tank made. One which featured cannon to attack targets such as artillery pieces and gun emplacements, and the second type would be a transport version, intended to carry fuel, ammunition and other supplies to support the attacking tanks. This version would also be used as a troop transport to carry infantry ashore in relative safety. The cannon armed version was nicknamed "Drake" and the cargo version was known as "Hen" as these are the male and female terms for ducks.
During testing it was discovered that the side sponsens of the standard Male tank were unsuitable for water-born operations as the gun ports were too low relative to the water line. To remedy this, it was elected to use a single 6 pdr cwt QF cannon and mount it to the right of the driver's position. This had two benefits, firstly it reduced the weight by halving the amount of cannons and secondly, the gun assembly was now positioned above the water line which greatly reduced the risk of flooding. To make room for the breech and gun crew, the engine and transmission were moved aft. This had the added benefit of correcting the centre of gravity. Other modifications for the Drake included a fresh air snorkel for the engine and crew as the danger of passing out whilst at sea was considerable. The body panels were sealed tightly, the exhaust was extended to stop ingress from any rogue waves and a radiator vent was positioned to the rear of the roof. Buoyancy tubes were added to the flanks and front of the tank to keep it afloat. The floats were jettisonable after the tanks leave the water.  Despite the best efforts to seal the tank, water build-up was still inevitable so a bilge pump was installed. One of the other noticeable, but possibly most important external changes from the standard British heavy tanks was the addition of hinged paddle plates to every 6th track link which provided driving motion whilst afloat. The Hens differed from the Drakes by having two sponsens fastened to each side which had two purposes. The first of which was to increase the internal volume of the vehicle for better storage/troop capacity. And secondly it added to the vehicles buoyancy without the need for the Drake's flank buoyancy tubes. Machine gun ports which were sealed with wax until the Hen came ashore, were fitted at various points along the length of the hull which enabled troops to fire at enemy infantry. Trials for the first Drake and Hen took place at Conwy Morfa beach where any remaining  teething issues were worked out and top secret training for the crews was undertaken during June 1917.
By mid July, 32 Drakes and 32 Hens were en-route to the Aegean Sea. The assault was to begin at 05:00 on the 8th of August across two beaches on Cape Helles with full fire support and submarine cover from the Royal Navy and aerial reconnaissance was provided by the Fleet Air Arm.
The amphibious assault caught the Ottomans off guard which allowed the first of the British armour to make it to the beach before the artillery started firing. In total, 34 Drakes and Hens were lost or knocked out during the first day of what became known as The Second Battle Of Gallipoli. After the second day of fighting, the port in Morto Bay was secured which allowed reinforcements of standard Mark.IV tanks to be deployed which then took over the fighting from what were collectively called "the Ducks" (Drake and Hen amphibious vehicles). Those Ducks that survived were immediately transported in secret back to Britain where they would link up with a further 20 Ducks that were fresh from the factory. These vehicles were to be used in another amphibious landing in Nieuwport, Belgium which was planned for the 9th of September but was held back until the 11th due to inclement weather. Most of the same tactics that were employed a month earlier were used during this new assault, codenamed Operation Hush.
Sir Douglas Haig was personally in charge of this operation and was thrilled to see his Ducks in action first hand. British forces managed to re-capture the port and bridgehead over the Yser and advanced 6 miles inland before a counter attack by the German Army drove the British forces back to the sea.
Although the initial attack was successful, overall, Operation Hush was widely considered a complete failure as the advancements in the Third Battle Of Ypres fell disappointingly short of what was expected which meant that the British and French forces could not link up with the amphibious assault group in Nieuwport.
The Second Battle Of Gallipoli continued to be fought through 1918 and was much more successful than the first battle. The forces of the Entente pushed hard along the Dardanelles Straight and captured Gallipoli. By taking control of the Ottoman straits. The Ottoman capital at Constantinople was exposed to bombardment by Entente battleships and became cut off from the Asian part of the empire. With the Ottoman Empire defeated, the Suez Canal was then safe and the Bosphorus and Dardanelles straits would be open to Entente supplies to the Black Sea and warm-water ports in Russia. This success was due in part to the strong foothold the Drakes and Hens provided to the Entente forces in the crucial first few hours of the assault at Cape Helles.
The doctrines that were deployed during the Second Battle Of Gallipoli would be studied by many military strategists around the world for the next century.

Here's my concept sketch, drawn almost two years ago 😬

Cool! Like the idea of the flaps on the tracks to provide forward motion in the water.

A logical and very well-expressed piece of written whiffery.  You have every reason to be proud of it......I would be!

Terrific story and models to accompany it   

Quote from: NARSES2 on December 26, 2023, 06:25:08 AMTerrific story and models to accompany it   

Yup ...what hims said     

Very cool idea, and they look really nice. Am I wrong in thinking these are based on the 1:72 scale Emhar kits?

Quote from: Jakko on December 27, 2023, 02:15:03 AMVery cool idea, and they look really nice. Am I wrong in thinking these are based on the 1:72 scale Emhar kits?

Thank you very much! You are wrong however. These models are built from Airfix's 1/76 Male kits ☺

Very good work on that.

Clearly not for the ANZAC sector.. .have you seen those hills 

Quote from: buzzbomb on December 27, 2023, 11:54:06 PMVery good work on that.

Clearly not for the ANZAC sector.. .have you seen those hills 

I know, there's no chance of these tanks making it up those without at least 12 breakdowns each 

Quote from: RAFF-35 on December 27, 2023, 08:29:05 AMThese models are built from Airfix's 1/76 Male kits ☺

Ah, OK, forgot about that one

What a brilliant idea. Another front for whiffery, WW1 armour.

Excellent stuff 

Quote from: stevehed on December 28, 2023, 08:57:19 AMWhat a brilliant idea. Another front for whiffery, WW1 armour.

Thank you very much! WW1 armour whiffs is an area ripe for picking as there was no standard design philosophy for tanks so anything goes!

Quote from: RAFF-35 on December 29, 2023, 01:13:39 AM

Quote from: stevehed on December 28, 2023, 08:57:19 AMWhat a brilliant idea. Another front for whiffery, WW1 armour.

Thank you very much! WW1 armour whiffs is an area ripe for picking as there was no standard design philosophy for tanks so anything goes!

And no computer modelling, so it was a case of building it first and then finding out whether or not it worked.