The Mass Transit Railway was built in the 1960s to cope with the increase of population and traffics of urban Hong Kong. Since its opening in 1970, MTR has been one of the most important traffic systems in Hong Kong, to the point many people identify locations according to nearby MTR stations.
During the Resources Wars, the colonial government, seeing that the home country was destroyed under nuclear attack, as well as the increasing aggression of China, authorized the reinforcement and construction of shelters in underground MTR stations and some parts of its tunnels. However, the structure of MTR itself, as well as the lack of resources due to the destruction of the UK and international trade routes, meaning that shelters that can withstand nuclear attack were impossible to build. The government claimed that the MTR shelters can withstand nuclear attacks anyway, hoping to calm the population despite the situation.
A combination of luck and engineering skills proved that MTR shelters are more sturdy than expected. During the invasion of Hong Kong in 2066, most parts of the MTR system remain more or less functional, with the exception of the cross-harbor tunnel being flooded, as well as several surface railways being destroyed.
During the reign of PRC, some parts of MTR were repaired, and its service reopened more or less as before the invasion. However, some parts of the tracks were connected to the Kowloon-Canton Railway, and some trains were conscripted to transfer soldiers and goods between Hong Kong and China.
In 2077, during the US invasion of Hong Kong, several parts of MTR were damaged during the attack, including the cross-harbor tunnel, Tate's Cairn tunnel, as well as some other surface parts. After the US forces took control of urban Hong Kong, MTR once again resumed its service, although in a limited way.
During the Great War, many citizens, believing that the shelters will once again protect them, fled into the MTR shelters to seek refuge. While many shelters remained intact during the nuclear attack, its air filtration system proved not sufficient to remove radiation from the air. As a result, many died within the shelters, while most survivors became ghouls.
After reorganizing themselves, survivors began clearing the collapsed tunnels and soon establish connection between the shelters. Some later ventured beyond the tubes and started scavenging the ruins above them, and made contact with other groups such as the Royal Hong Kong Regiment, Society for National Glory, as well as other wastelanders. Trades are soon established between different groups for supply of food, water, tools, and other necessities.
Intended as temporary shelters and not for nuclear apocalypse, MTR shelters rarely have anything beyond simple water and air filtration system, as well as generators for power. As a result, while some settlements have agreed to sell electricity and filtered water for necessities, most shelters have no viable means for trading. However, their location beneath ruins of urban Hong Kong means that their inhabitants have relatively easy access for scavenging. Therefore, many ghoul inhabitants in MTR shelters adopt the life of scavengers, walking within the collapsed ruins of Hong Kong to find their fortune.
While it varies from shelter to shelter, most MTR shelters are headed by a "manager", who acts as the mayor of the settlement. Some larger settlements have a kind of representative council that contributes to the decision-making process, but most of them are, in effect, autocracy by manager.
As many shelters in MTR are protected by the Royal Hong Kong Regiment, the highest-ranking officer in the local garrison often have influence on the administration on shelters, although it is rare for them to meddle affairs beyond foreign trading and security.
Kwun Tong Line (Green)
One of the more intact part of MTR system. The collapse of cross-harbor tunnel flooded several parts of the tunnel. While still accessible from tunnel in Tsuen Wan Line (Red), it prevents carts and trains from moving directly across the harbor. The flooding also flooded Tsim Sha Tsui Station and its shelter.
Green Line surfaces at Kowloon Bay Station, which also contained its trainyard. By scavenging replacement parts from it, metro dwellers managed to repair most of the railway between Jordan and Kwun Tong, meaning that produced goods from factories in Kwun Tong and scavenged goods from Kowloon can be distributed by powered or pulled carts and trains.
Kowloon Tong station is located beneath a KCR station that bears the same name, and a street away from the Osborn Barracks. Since it is located in a low-density "suburban" residential district, in which most residents are wealthy enough to either secure places in private shelters, or had left Hong Kong before the Great War, its shelter remained mostly empty. Soon after the Royal Hong Kong Regiment reorganized in Osborn Barracks, the station, as well as its half-empty shelter, was taken by RHKR as its first outpost.
Since then, more people regrouped or joined RHKR, many of them making a residence in the shelter. A tunnel, presumably dug before the war as secret escape route, connected between the shelter and the barracks. While merchants and civilians can pass the station, access to either the surface or the shelter is restricted.
Kowloon Bay station is located right outside the tunnel towards the underground portion of the Green Line, as well as above the trainyard that served the line before the war. During the Chinese occupation, the military renovated some parts of it, in order to help to transport cargo from the Kwun Tong industrial district, from here through the now-connected rails to Canton.
While many equipments were destroyed during the US invasion and the Great War, it is still being seen as a vital source for replacement parts for the metro system and was a gathering zone for scavengers before the Royal Hong Kong Regiment captured it in around 2120. Since then, the station has been the base for its East Kowloon Company and its expansion towards Garden City.
Although Garden City achieved (limited) independence from both US remnants and RHKR, the garrison still holds Kowloon Bay and the trainyard for its strategic locations and machinery.
Tsuen Wan Line (Red)
Similar to Green Line, Red Line also suffered floods that destroyed Admiralty Station and parts of the cross-harbor tunnel. Surfaced at For Kong (Cargo Port) Station, it also serves as a connection between Kowloon ruins and the industrial region of Tsuen Wan. However, it suffered more damage during the Great War, making its railway still not re-connected as of now.
Sham Shui Po
Poseidon Estate (Lai Chi Kok)
Shatin Line (Purple)
Unlike other lines in Kowloon, Purple Line was mostly destroyed during the Great War. While several shelters were functional, if not isolated from others, the only tunnels that were repaired were the one between Kai Tak and Tsz Wan Shan, as well as Hung Mui Kuk to Wo Liu Hang. Tate's Cairn Tunnel, the tunnel between Tsz Wan Shan and Hung Mui Kuk, collapsed during the US invasion and was still repairing due to it being systematically destroyed by retreating PLA forces.
The Kai Tak Station Shelter, located right below the Kai Tak Airport, is currently under the control of a group of US remnants, most of them decedents of US soldiers in the region when the bombs fell. While many died or ghoulified, US remnants are still a notable force to be reckoned with, mostly because they still have access to US arsenal in the airport, including a functional reactor that provides vital powers for the factories in Kwun Tong.
Tsz Wan Shan
Tsz Wan Shan station is one of the deepest stations in MTR system. Located way beneath the Tsz Wan Shan estates, its shelter is notably larger than those in other stations. However, during the Great War, one of the nuclear bombers from China crashed into the estates after being intercepted when it was en route to bomb the Kai Tak Airport. While the nuclear warhead inside did not explode, its radioactive substances leaked down the ventilation system of the shelter. As a result, most of the refugees died or became feral ghouls shortly afterward, killing the rest survivors.
Several attempts by other parties were made to reclaim the shelter, fix the ventilation system, or to recover the bomb. Most of them failed, with some merchants and scavengers managing to secure some of the less polluted sections as a base for scavenging the estates, as well as to rebuild the Tate's Cairn Tunnel.
Island Line (Blue)
Being on the main island of Hong Kong, most of the Blue Line were reduced to collapsed tunnels filled with radioactive debris along with the surface city. As of now, tunnels west of Western Market Station were repaired, as part of New Hong Kong's plan to reach Kowloon without crossing the glowing harbor. Tunnels from Admiralty to the large shelter in Valley Station were also repairing in progress, but constant collapse from the ruins above prove hard to maintain connection.
Some inner members of New Hong Kong have access to a secretly-repaired service tunnel that leads straight to a private shelter between Quarry Bay and Sai Wan Ho. Dubbed "Swire Shelter", this privately-built shelter houses the remnants of pre-war cartels that ruled Hong Kong before and would rule New Hong Kong like the old days.
Belcher Shelter is the founding place of New Hong Kong, a faction that claims to be successor of the pre-war colonial government. Since the foundation of Tong Sai, a settlement that located above Belcher Station at the surface, the importance of Belcher diminishes, but it remains more or less famous for being the proper entrance of Tong Sai. Both New Hong Kong and Swire have comparatively much militia stationing in the station for security reasons.
Located underneath the commercial district with the same name, Causeway Bay station is one of the largest stations before MTR shelters were built. Before and during the renovation in the 2060s, Causeway Bay station expanded several times, to the point it practically covered most of the district in a network of underground plazas of shops. As a result, the underground city was also one of the largest shelters in the system.
During the Great War, Causeway Bay, like other parts of urban Hong Kong, was heavily bombed, causing many parts of the underground city to collapse, with the survivors turning into ghouls due to radiation leaking from the ventilation system and the collapsed surface.
Despite the dire situation, Causeway Bay Shelter still remains to be one of the more populous and important settlement, partly because of its proximity to the collapsed ruins above, thus serving as a good scavenging outpost. Its sheer population base, while being hard to maintain stable, also provides many skilled pre-war workers, who maintain the knowledge and radiation resistance for New Hong Kong to repair and maintain its technology.
Located near the Swire (Taikoo) Dockyard, between Quarry Bay station and Sai Wan Ho station, Swire Shelter is a privately-owned shelter built by the Swire Group, an influential corporation since the foundation of Hong Kong. When the colonial government asked Swire to support the MTR shelter project, Swire agreed with the condition of having its own private shelter beyond the control of the government. It accepted the offer, and the Swire shelter was built in 2065.
Unlike the makeshift public shelters within MTR system, Swire Shelter is a fully functional shelter similar to Vault-Tec vaults, complete with air filtration system, water purifier, underground greenhouses, as well as other equipment for prolonged isolation. It was designed to house 500 people, but only house 300 people for increased life quality of the directors.
Because it appeared only in the most confidential documents, and it isolated from the MTR system, it remained undiscovered from both the Chinese and US forces and was gradually expanded and populated by Swire's board of directors, along with hundreds of employees that were deemed loyal to the corporation. It was sealed during the Great War, mostly unaffected by the end of the world. From then, the shelter was ruled by the directors like a corporation, with many aspects of life being firmly controlled.
The first expedition team resurfaced 30 years after the Great War, and started to explore the devastated city. While the surface was reduced to radioactive ruins, Swire repaired a service tunnel beneath the Blue Line, clearing a way all to the Belcher Station. Swire soon assumed control of the less-devastated Western district with its relatively powerful private militia.
Today, the board of directors, mostly the descents of the original directors, continued to live and rule the Swire shelter, and regularly uses its influence to control New Hong Kong. In order to prevent infiltration and sabotage, the existence of Swire Shelter is still kept as secret, and any potential infiltrators would be dealt with, without hesitation.