Shanghai Bunkers | Forgotten Symbols of Resistance [part 1/2]

Few (local) people know, or care, that thousands of pillboxes, bunkers, and shelters had been built in Shanghai between the 1930s and 1970s. While most of these fortifications have been demolished in recent decades, quite a few can still be seen today, scattered throughout the city although their conditions vary greatly. Some are left to be forgotten, some have been repurposed or integrated into their surroundings while others are used to illustrate China’s historical narrative, set by the Communist Party of China.

For almost two years, I have been researching these bunkers, trying to locate, and list, the remaining ones and have invited others to join me in what has become a bit of a passion project. As of June 2023, nearly 250 bunkers are listed and we have collectively located close to 200, but there are most likely many more left. My silly quest even got the attention from the nice people at That's Shanghai, Sixth Tone and the South China Morning Post (YouTube).‍

Please note, this article is an amateur's attempt to piece together the history of Shanghai's bunkers, as well as a summary of my conclusions. Since this is a work in progress, and new discoveries are still being made, content may be revised at any time.‍

Let’s start with the basics: a bunker is a defensive military fortification designed to protect people and valued materials from ground or aerial attacks. Bunkers are partly or completely underground, in contrast to blockhouses, which are mostly above ground. A bunker is most commonly made from reinforced concrete, but bricks, rocks, gravel and steel are used as well. Not all bunkers are the same and serve a variety of purposes. A pillbox is dug-in guard post with loopholes for active defence and a casemate is like a pillbox, but (much) bigger to fit artillery pieces. Other bunkers can be used as munitions storage, and while an air-raid or (nuclear) bomb shelter provides solid protection against bomb strikes, it is less suited for active defence against ground assaults. For the sake of simplicity, I have chosen to refer to all types of military fortifications as bunkers, even though some of them technically are not. My research indicates Shanghai's bunkers were built during four distinct periods:

Between 1935-1937, by the governing Chinese Nationalists (KMT) to defend Shanghai against a Japanese invasion [part one].

The Japanese would erect several dozen fortifications between the end of the 'Shanghai Incident' in 1932 and the start of the 'Second Sino-Japanese War' in 1937. These fortifications would have been not much more than (fortified) roadblocks or checkpoints, made from sandbags or possibly bricks, and were rather of a temporary than permanent nature. The Japanese were not unique in this: as tensions rose in the early 1930s, the Chinese Nationalists, Brits, and French would do the same in their areas of control.

Within six months of launching their full-blown invasion of China, the Japanese had taken control of the Yangtze River Delta and by the middle of 1938, they sought to consolidate and control their newly conquered territories with a minimum amount of troops. The Japanese would therefore construct a series of blockhouses and watchtowers along strategic positions, such as railways, water crossings and main roads. These fortified positions were made from bricks, several layers thick. The remaining Chinese resistance did not possess any heavy weaponry (anymore), so brick made fortifications provided enough protection from small arms fire.

Initially victorious, the Japanese war machine started to stall and by the beginning of 1943, Japan found itself on the defensive. Most western nations had declared war on Japan, while the Chinese managed to hold out in Central and Western China, with material and financial support from (mainly) the Americans and the Russians. From unoccupied Chinese territory, Allied bombers could target Japanese positions in the Yangtze River Delta, while simultaneously, the Americans were pushing back the Japanese in the Pacific. It is around this time a shift in the Japanese defences can be detected: the warrior's way, perhaps no longer applicable on the modern battlefield, was ignored, and lightly fortified brick blockhouses gave way to bunkers made from reinforced concrete and steel.

Out of all factions involved, the number of remaining Japanese bunkers appears to be the lowest. For most of their 13-year involvement in Shanghai, the Japanese were on the offensive and the widespread use of bunkers did not fit in their vision of conquest. Perhaps of some relevance too, the centuries-old "Bushido" (way of the warrior) was still very influential on military tactics of the time, and Japan's military leadership favoured (honourable) attack to (cowardice) defence. When the war ended, many Japanese fortifications were demolished by Japanese POWs, and possibly as well as by revengeful Chinese, who were keen on eliminating any reminders of Imperial Japan's brutal occupation.

The Chinese Nationalists (or Kuomintang) under the leadership of Chiang Kai-shek would construct thousands of fortifications on two separate occasions (first in 1937 and again in 1949) but against two different opponents.

Almost right up until the start of the Second Sino-Japanese War in 1937, Chiang Kai-shek followed a strategy of "first internal pacification, then external resistance" and was focussed on eradicating the Communist Party of China (by then under leadership of Mao Zedong) rather than resisting the fast-encroaching Imperial Japanese. Only after the 'Xian Incident' in 1936, did he reluctantly make peace with the Communists and started preparing for the inevitable war with the Empire of Japan.

The German general Alexander von Falkenhausen, who served as a military advisor to Chiang Kai-shek and helped modernise the Nationalist army between 1934-1938, recommended Chiang to fight a war of attrition, arguing the Japanese could not win a long-term war. Von Falkenhausen advised to construct several fortifications at strategically important regions to slow down Japanese offensives. One such region was the Yangtze River Delta, which consisted out of Shanghai, Hangzhou and Nanjing, China's richest and most industrialised region, as well as Chiang Kai-shek's political powerbase. Similar advice was given previously by another German military advisor called Hans von Seeckt, who arrived in China one year earlier than von Falkenhausen, but his advice was not followed through since Chiang was still focussed on fighting the Communists first.

The 'Jiangnan National Defence Project' would consist out of three heavily fortified lines to protect the approach from Shanghai to Hangzhou and Nanjing, consisting of more than 1,700 column shaped pillboxes, observation posts, minefields, (anti-tank) trenches, and barbed wire. The first defence line ('Haijia Line') ran from the Hangzhou Bay to Taihu Lake and guarded the western flank to Hangzhou. The other two lines ('Wufu Line' and 'Xichang Line') were erected north of Shanghai, between Taihu Lake and the Yangtze River, and covered the most direct approach to Nanjing. These fortified lines were supplemented by forward positions in Shanghai's northern and western suburbs, sometimes referred to as the 'Songhu Line', and along its Pudong coastline. 

Among western observers, the defence works were reminiscent of the large-scale fortifications built by the Germans during WWI and were therefore colloquially known as the "Chinese Hindenberg Line". While construction of the massive defence works was initiated sometime in 1935, most of the fortifications seem to have been built between late 1936 and early 1937. During an inspection by Chiang Kai-shek in January 1937, it was revealed that the defence lines between Shanghai and Nanjing were virtually non-existent, so (a possibly furious) Chiang ordered the immediate construction of the fortifications.

These defensive works were never meant to impregnable, but rather to slow down an enemy advance and causing as many enemy casualties as possible. When a line couldn't be held anymore, Chinese troops would retreat to the next one and further stall the Japanese advance as long as possible. Meanwhile, new troops could be trained and equipped and by putting up a proper fight, Chiang Kai-shek hoped he could tempt the neutral western powers to join, or at least openly support, his fight against the Empire of Japan.

When the Japanese launched their assault on 13 August 1937, the "Chinese Hindenberg Line" was estimated to be 70% completed. Unfortunately, the defensive lines were not utilised to their fullest extent: after the fall of Shanghai, the demoralising sight of thousands of retreating soldiers led to many of the lines' defenders abandoning their positions. However, the failure of the defence works wasn't purely human caused. The lines were undermanned and lacked artillery, which was still enroute from Germany to China. Many fortifications had (crucial) flaws, such as too large loopholes (which fully exposed the defenders), protruding rooftops (easy to spot), were made from inferior concrete that "could be crushed by hand" and were designed to withstand only frontal attacks, so they could be easily taken by encirclement. The endemic corruption amongst the Nationalist military leadership also led to a substantial amount of the 30-million-yuan budget ending up in their pockets and arguably contributed to all the delays in construction. While Chang Kai-shek had boasted to Chinese and foreign press his defence lines could stall the Japanese for at least half a year, it would take the Japanese less than one month to cross the 300+km distance between Shanghai and Nanjing without much heavy resistance. 

After Japan's surrender in 1945, and so with the common enemy gone, it didn't take long before the uneasy alliance of the Nationalists and Communists collapsed and the fight for control of China resumed in 1946. While the Nationalists had the upper hand before 1937, the tide had turned in favour of the Communists at the end of the Second Sino-Japanese war: the Red Army had grown to over one million men and was supplied by the Soviet Union, who turned over all their captured Japanese weapons. But, most importantly, the Communists had the people's support: disillusioned but well-equipped Nationalist troops joined the Red Army and the initiated land reforms attracted massive numbers of landless poor to the Communist cause, providing an almost unlimited supply of manpower for both combat and logistical purposes. 

After securing several major victories in Northern China, the Communists started pushing further south with the situation for the Nationalists looking increasingly dire by the end of 1948. In December of that year, Chiang Kai-shek appointed Tang Enbo, a Nationalist general who had fought 'rebel' Communists and the invading Japanese before, the commander-in-chief of the Nanjing-Shanghai-Hangzhou Garrison and made him responsible for the all-important defence of Shanghai, China's economic centre and where Chiang hoped to gain the upper hand again.

Following Chiang's instructions, Tang set up the "Shanghai Fortification Construction Committee" and ordered his engineers to start work on Shanghai's defences in January 1949. The fortifications would be based on those built by Yan Yishan, a northern warlord supportive of the Nationalists, around the Shanxi capital of Taiyuan. Anticipating a Communist assault, Yan had built more than 5,000 bunkers over the city's surrounding rugged natural terrain early 1948. Outnumbered almost three to one, Yan managed to hold out for more than six months before the inevitable happened and the Communists took Taiyuan late April 1949.

The 'Greater Shanghai’s Line of Defence' consisted out of three components: the 'outlaying positions' in the outer suburbs would protect the approach to Shanghai, the 'main positions' on the city’s borders would guard entry into the city and the 'core positions' in downtown Shanghai would allow for the city's defence until the bitter end. Tang planned to build more than 4,200 fortifications made from reinforced concrete and divided into four types: A (甲), B (乙), C (丙) and a main fort (主堡). Based on what I've found so far, I think these types could refer to a smaller and a larger version of the same type of pillbox, a two-storied command post, and possibly a shelter or ammunition depot.

The small and large pillbox, both dug-in machine gun fortifications, were called 'sub fortresses' (子堡) and 3,042 of them were built. The core of the pillbox was round shaped with a rectangular extension, which provided access. It had loopholes, with stepped embrasures and protective eaves, facing every direction and the rectangular extension had one or two entrances, which could be shut with steel lids or doors. The top had three or four small square holes for ventilation. Each pillbox could hold two to four gunners. Four of these pillboxes were usually arranged around a main fort, called a 'mother fort' (母堡), forming a bunker group. The two or three storied main fort acted as the group's command and observation post and was made up from three round shaped pillboxes (without the rectangular extension) with a circular part on top and a lookout. At least 78 of these main forts are known to have been built, but only six remain. The pillboxes and main fort were often camouflaged, were connected by trenches, and were surrounded by barbed wire, mines, and (hidden) sharpened bamboo sticks. Each bunker group deployed at least one platoon (30-40 men) and were equipped with light and heavy machine guns. 

Construction of all these fortifications was assigned to the 'Lugenji Construction Company', which was already linked to the Nationalists through its owner, Lu Genquan. Lu came from the same village as Du Yuesheng, Shanghai's most famous gangster and Nationalist collaborator. Before Nationalist projects became its primary focus, Lu's construction company built various banks, hospitals, and residential projects in Shanghai, as well as the 'The Paramount', the city's largest (and most notorious) ballroom with sprung wooden dance floor. 

From ballrooms to bunkers, the Lugenji Construction Company sure left its mark on the then Shanghai skyline (right picture by Harisson Foreman).