Gin Drinkers Line The Gin Drinkers Line ( ) or Gin Drinker ' s Line was a British military defensive line against the Japanese invasion of Hong Kong during the Battle of Hong Kong in December 1941 , part of the Pacific War . The concept came from France ' s Maginot Line , built after World War I . The British believed the line could protect the colony from Japanese invasion for at least six months and even called it the " Oriental Maginot Line " ( ) . The Japanese generals also believed the line would stop their advance until the scouts found out the line was very weak . For example , only 30 soldiers were defending Shing Mun Redoubt in Battle of Hong Kong with a capacity of 120 . Geographical location . The Line ' s name originated from Gin Drinkers Bay , a former bay in nearby Kwai Chung , New Territories ( now reclaimed and part of Kwai Fong ) . It passed through Kam Shan , the Shing Mun Reservoir , Beacon Hill , Lion Rock , and Tate ' s Cairn , ending at Port Shelter in Sai Kung ; its total length was 18 kilometers . Its key points were the stretch between Beacon Hill and Sha Tin Pass , and the Shing Mun Redoubt , the latter of which also housed command HQ for the Line . The Line made use of the mountains north of the Kowloon Peninsula and was strategically important in preventing any southward invasion from the New Territories . Construction . Construction lasted from 1936 to 1938 . The Line was not actually a solid defensive line but a series of defensive positions linked together by paths . Bunkers , concrete fortified machine gun posts , trenches and artillery batteries were built along the line ; however , this artillery support may have been insufficient . Shing Mun Redoubt . Defensive headquarters were located at Shing Mun Redoubt , which had an observation post ( acting as Headquarters of the redoubt ) that could call artillery support from Mount Davis battery and Stonecutters Island Fort , and four pillboxes ( PB400 - 403 ) fitted with Vickers machine gun and Bren LMG . There were 1 . 5 meter deep defensive channels or trenches , named after the roads of London such as Charing Cross , to provide familiarity to the English soldiers of the Middlesex Regiment . During the Battle of Hong Kong . 8 December 1941 : initial contact . On the morning of 8 December 1941 , Japanese forces bombed Kai Tak Airport , wresting control of the skies from the British and initiating the Battle of Hong Kong . At noon , the Japanese advance guard crossed the Shenzhen River to invade the New Territories . The northern garrison fell back to the Gin Drinkers Line , destroying roads and bridges on the way to make it more difficult for the invaders . By dusk , the Japanese had taken Tai Po . There were only three British Army battalions manning the Gin Drinkers Line : the 2nd Battalion , Royal Scots in the west , the 2 / 14th Battalion , Punjab Regiment in the centre and the 5 / 7th Battalion , Rajput Regiment in the east . It was hoped that they could hold for at least three weeks and inflict some casualties on the Japanese . 9 December : Japanese sneak attack . On 9 December , Japanese advance scouts of the 228th Regiment headed towards Tai Mo Shan , and discovered that British defences were weak at " 225 High Ground " near Shing Mun Redoubt and Shing Mun Reservoir . The high ground also meant dominance over all positions in the western portion of the Line . Therefore , the Japanese advanced a sneak attack . At 9pm that evening , the lieutenant in charge and ten elite soldiers began the sneak attack . Combat engineer s successfully breached the barbed wire and destroyed bunkers . By 7am on 10 December , they had taken the high ground and 27 POWs , opening a breach in the Line . The success surprised Japanese commanders who had thought at least a month was required to break the British defences , and thereby diverted more forces from mainland China to boost manpower . They also thought that a premature breakthrough would lead to rear forces and artillery troops falling behind , but ultimately agreed to launch a general assault . 10 December : general assault . Japanese forces then opened a two - pronged assault on the Gin Drinkers Line . By the next day , they had already claimed Kam Shan and Tate ' s Cairn . Major General Christopher Maltby knew that the position was untenable and at noon decided to withdraw the garrison to Hong Kong Island to preserve its strength , signalling the official defeat of the Line . Defenders to the west of the Line began retreating towards the Island at 8pm . The Rajput Battalion stayed behind as a rear guard , only retreating on the morning of 13 December towards Devil ' s Peak and Lei Yue Mun towards Hong Kong Island . This was also the final retreat of British forces from the Kowloon Peninsula . Reasons for failure . Similar to the Maginot Line , the Gin Drinkers Line was generally considered to be a complete failure . The line and the whole of Kowloon were abandoned by the British troops in just two days . There can be said to be three main reasons : Today . Most of the Line ' s remains cannot be found ; however , there are still some defensive structures left at Shing Mun Redoubt , and bunkers at Lion Rock , Tate ' s Cairn and Port Shelter .