I have been researching the history of railways in Japan. My interest has been drawn by the use of Cape Gauge as the early standard gauge in Japan.
Cape Gauge is very close to the Metre-Gauge that many of the secondary lines in France. It is the same track gauge that was used in a number of different British colonies.The photographers notes say: JNR 3′ 6″ Gauge Class C10-8 on a turntable in Oikawa Railways Senzu station in July 2001. It was built by the Kawasaki Heavy Industries Rolling Stock Company, Kisha Seizō in 1930, (c) D. Bellwood. 
Railways with a track gauge of 3′ 6″ (1,067 mm) were first constructed as horse-drawn wagonways. From the mid-nineteenth century, the 3’6″ gauge became widespread in the British Empire (although it was not used in East Africa or India) and was adopted as a standard in Japan and Taiwan.
There are approximately 112,000 kilometres (70,000 miles) of 1,067 mm gauge track in the world.The photographer’s note says: Class C11 is a type of 2-6-4T 3′ 6″ Gauge steam locomotive built by the Japanese Government Railways and the Japanese National Railways from 1932 to 1947. A total of 381 Class C11 locomotives were built. This is JR Hokkaido C11 207 hauling a Niseko tourist service in September 2014, (c) ウツダー, Japan. 
The article on this subject on Wikipedia  says that one of the first railways to use 3′ 6″ (1,067 mm) gauge was the Little Eaton Gangway in England, constructed as a horse-drawn wagonway in 1795. Other 3′ 6″ gauge wagonways in England and Wales were also built in the early nineteenth century.
In 1862 the Norwegian engineer Carl Abraham Pihl constructed the first 3′ 6″ gauge railway in Norway, the Røros Line. Japan Railway and Transport Review carried an article about Norwegian Railways in 2002. 
In 1865 Queensland Railways were constructed. Its 3′ 6″ gauge was promoted by the Irish engineer Abraham Fitzgibbon and consulting engineer Charles Fox.
In 1867, the construction of the railway from the Castillo de Buitrón mine to the pier of San Juan del Puerto, Huelva, Spain, began. The width was 3′ 6″ (1,067 mm).
In 1868 Charles Fox asks civil engineer Edmund Wragge to survey a 3′ 6″ railway in Costa Rica.
In 1871 the Canadian Toronto, Grey and Bruce Railway and the Toronto and Nipissing Railway were opened, promoted by Pihl and Fitzgibbon and surveyed by Wragge as an engineer of Fox.
In January 1872, Robert Fairlie advocated the use of 3 ft 6 in gauge in his book Railways Or No Railways: Narrow Gauge, Economy with Efficiency v. Broad Gauge, Costliness with Extravagance. 
1872 also saw the opening of the first 3′ 6″ gauge railway in Japan, proposed by the British civil engineer Edmund Morel based on his experience of building railways in New Zealand. .
On 1 January 1873, the first 3′ 6″ gauge railway was opened in New Zealand, constructed by the British firm John Brogden and Sons. Earlier built 4 ft 8 1⁄2 in (1,435 mm) and broad gauge railways were soon converted to the narrower gauge.
Also in 1873, the Cape Colony adopted the 3′ 6″ gauge. . After conducting several studies in southern Europe, the Molteno Government selected the gauge as being the most economically suited for traversing steep mountain ranges. Beginning in 1873, under supervision of Railway engineer of the Colony William Brounger, , the Cape Government Railways rapidly expanded and the gauge became the standard for southern Africa. 
In 1876, Natal also converted its short 10 kilometres (6.2 miles) long Durban network from 4 ft 8 1⁄2 in (1,435 mm) standard gauge prior to commencing with construction of a network across the entire colony in 1876. 
Other new railways in Southern Africa, notably Mozambique, Bechuanaland, the Rhodesias, Nyasaland and Angola, were also constructed in 3′ 6″ gauge during that time.After 1876In the late nineteenth and early twentieth century numerous 3′ 6″ gauge tram systems were built in the United Kingdom and the Netherlands.
The precise reason why a track gauge of 3′ 6″ in (1,067 mm) (also known as “Cape gauge”) came to be selected as the early standard gauge in Japan remains uncertain. It could be because 3’6″ was supposedly cheaper to build than the international standard “Stephenson gauge” of 4 ft 8 1⁄2 in (1,435 mm), or because the first British agent, whose contract was later cancelled, ordered iron sleepers made for the narrower gauge. It seems most likely, however, that Morel’s previous experience building Cape gauge railways in similar New Zealand terrain was a significant influence, and Cape gauge became the de facto standard.
As a further commentary on the 3′ 6″ gauge, readers might want to consult Japan Railway and Transport Review which carried an article about the 3′ 6″ gauge in 2002. 
Japan’s Shinkansen lines are all built to Standard Gauge, because trains are more stable, and can go faster, on wider track. Some other lines in Japan use 1,372 mm (4′ 6″), 762 mm (30″) gauge or 610 mm (24″) gauge. But the majority, over 83% in terms of distance, of Japan’s railways are built to Cape Gauge, 1,067 mm (3′ 6″). The name comes from its adoption in 1873 by the Cape Colony (later part of the Union of South Africa). But by then it had been around for nearly a century, originally for horse-drawn railways in England and Wales, and later steam railways around the world, including Australia, Canada and other locations. And, as of 1872, Japan, where it is known as KyOki (OM, literally “narrow path” or “narrow track”). But compared to Standard Gauge, it’s never been all that heavily used outside of Japan. 
Currently there are 5 track gauges in common use in Japan. The most common gauge is 1067mm/3′ 6″, which forms the bulk of the JR Group network and connecting private railways. The others, already referred to above, were very kindly listed by Mark Newton in response to a query from me on the website http://www.jnsforum.com.  His notes are in italics below. There is also an article in the archives of the magazine, Japan Railway & Transport Review from January 1997 which reflects on the activities of railway companies in the private sector :
610mm – Tateyama Sabo railway (shown adjacent) in Toyama prefecture.  I think this would be the last non-museum/preserved line using 610mm gauge, which was once common for local and industrial railway operations, known as “keiben“,  throughout Japan.
762mm – the three former Kintetsu lines  … and the Kurobe Gorge railway (shown adjacent).  This gauge was also once very commonly used by keibenlines throughout Japan, but in many cases the lines were converted to 1067mm gauge and electrified as traffic increased, such as Kintetsu’s Yunoyama line. The famous Kiso Forest Railway was 762mm gauge. 
1067mm – JR Hokkaido, JR East, JR Tokai, JR West, JR Shikoku, JR Kyushu, all JR Freight operations on these lines, and many private railways and tramway, big and small. The reasons for choosing 3’6″ gauge for the original Tokyo-Yokohama line in 1872 are not apparent these days, but that choice greatly influenced subsequent government and private railway construction.
1372mm – Toei Shinjuku line,  Tokyu Setagaya line,  Toden Arakawa line,  Keio Teito Corporation lines,  and the Hakodate city tramway.  The once-huge Tokyo municipal tramway system was built to this gauge, plus some private railways and tramway in the Tokyo area. Some of these lines have been re-gauged twice, going from 1067mm to 1372mm, then 1372mm to 1435mm!Hakodate Haikara-gō is a vintage 1372mm gauage tramcar first operated in the city in 1918 and now restored for use on tourist runs in the summer, (c) 湯の川. 
1435mm – Shin Keisei railway, Hokuso Railway, Keihin Express Railway, Keisei Electric Railway, Eidan Ginza and Marunouchi lines, Toei Asakusa line, Yokohama metro, Hakone Tozan Railway, Nagoya metro, Kinki Nippon Railway/Kintetsu main lines, Keifuku Electric Railway, Eizan Electric Railway, Keihan Electric Railway, Kyoto metro, Osaka metro, Hankai Electric Tramway, Hankyu Electric Railway, Nose Electric Railway, Hanshin Electric Railway, Kobe metro, San-Yo Electric Railway, Hiroshima Electric Railway, Takamatsu-Kotohira Electric Railway, Chikuho Electric Railway, Nishi Nippon Railway main lines, Nagasaki Electric Tramway, Kumamoto city tramway, Kagoshima city tramway, and of course the JR Shinkansen network. So there’s more standard gauge trackage in Japan than you might think at first.
Historically there were a number of other gauges used. There were once a number of man-powered tramways, known as “jinsha kido”, some of which used 737mm gauge. Kaimaishi Iron Works and the Hankai Railway used 838mm. In northern Kyushu there were a number of local lines that used 914mm/3′ gauge. In total there have been 16 different track gauges used in Japan in the railway era. I’ve not gone into the various monorails and guideway lines there, as I’m not sure how you’d even measure their gauges! 
Edmund Morel (1840-1871) was a British civil engineer who was engaged in railway construction in many countries, including New Zealand, Australia, and Japan. He was the first foreign Engineer-in-Chief appointed by the Japanese government, for guiding and supervising railway construction.
A graduate of King’s College in London where he studied civil engineering, he was highly sought after to work with countries seeking to construct railroad systems, such as in New Zealand, Australia and North Borneo, which is now part of Malaysia.
Edmund Morel was clearly not one to shy away from a challenge. It was while he was working in North Borneo that he was asked to come to Japan by British envoy Sir Harry Parkes and help create Japan’s first railroad system. Edmund arrived in Japan on April 9, 1870. He had only 18 months to live.  On arriving at Yokohama, he at once proceeded to set out a line of railway between Tokei and Yokohama, 20 miles in length; the works on this, and on another length of 20 miles, between Kobe and Otaka, were commenced under him, but he did not live to see their completion. 
He assumed the role of Japan’s first chief engineer for railway and telegraph construction. His involvement in Japan was quite eclectic. Along with railway design he made proposals about the country’s education system and about engineering administration. It was as a result of his advice that Japan set up its Ministry of Public Works in December of 1870. It’s role was to find ways to bring in and utilize foreign technologies. 
The locomotives and rails for Morel’s railways were imported from England. Through discussions with senior government officials, Japan’s standard gauge of 1,067 mm (3′ 6″) was established.  Morel’s experiences in other countries predisposed him to the narrow gauge of 3′ 6″, in New Zealand contractors began laying track to the 5′ 3″ gauge from 1863 but all of it had been reduced to 3′ 6″ by 1870. Similarly, standard-gauge track laid in Indonesia from 1867 was gradually changed to 3′ 6″. (That gauge-change took time and was only completed during Japan’s wartime occupation.) 
As we have already noted, survey work for the 3′ 6″ line between Tokyo and Yokohama were begun in the spring of 1870 and the line was completed in May, 1872. The formal opening of the railway took place in the presence of the Emperor. “A general holiday,” says one account, “was declared for all government offices, and His Majesty the Emperor proceeded to the station dressed in ancient court costume, Naosbi, in a four-horse state carriage, accompanied by his suite in similar dress and wearing their swords.” A Cape Gauge (3′ 6″) Express train ‘Niseko’ bound for Otaru, Hokkaido, Japan. An steam locomotive type C62 (C623) and five old type passenger cars. The C62 type locomotive was the biggest and largest steam locomotive for passenger train in Japan, (c) Neko Ja Neko Ja. 
“During the first year from May 7, 1872 to December 31, the railway carried 495,000 passengers, and about 500 tons of freight. In this period the operating income came to 174,930 yen and operating expenses amounted to 113,464 yen, producing a profit of 61,466 yen.” 
Other government sponsored lines were started after the opening of the first railroad. In December of 1873 work was begun on a 27-mile line between Kyoto and Osaka, and entwined in 1877. A short line between Osaka and Kobe was opened to traffic in 1874. Long range plans called for the laying of trunk lines, but owing to the shortage of funds and internal disturbances culminating in the Satsuma Rebellion, the government was unable to launch large scale railway projects in the early years. 
Hudson built for the Limited Expresses of the old Cape-gauge (3′ 6″) Tokaido line, class C62, Hiroshima 1966, (c) Dr. Stephan Stoeckl. 
Although the government didn’t nationalize the railways until 1906, it took a strong central role in standardization, and apparently chose to continue with the gauge it had started with, causing most later railways to be built to that gauge. Some private railways chose other gauges, including standard gauge, and in particular a number of small regional railways used and still use 762 mm (30”) gauge. But most were built to Cape Gauge. 
In subsequent years, particularly from 1909 to 1920, the Japanese would try, repeatedly, to switch to standard gauge out of a desire for higher speed, heavier tonnage, or simply for ease of purchasing equipment overseas. Several of these attempts were put off by the government on military grounds, as the existence of an odd gauge made use of railway lines by a potential invader more difficult. By 1927, the nationalized Japanese Government Railways operated 12,864 km (7,993 mi) of track and it would have been very expensive to convert. And by then, the technology was entirely locally-made, and imports were no longer a concern. A preserved Japanese 3′ 6″ gauge JNR Class D51 2-8-2 locomotive in main line service in 2014 (c) C.C. Lerk. Cape Gauge (3′ 6″) EF62 1 at the Usui Pass Railway Heritage Park, April 2007, (c) RSA. This is a a Co′Co′ wheel arrangement DC electric locomotive type built between 1962 and 1969 
It wasn’t until the first high speed Shinkansen line was built in the 1960’s that Japan would finally get a large-scale standard gauge line. 
- https://en.m.wikipedia.org/wiki/3_ft_6_in_gauge_railways, accessed on 2nd January 2019.
- http://www.sumidacrossing.org/Prototype/StandardNarrowGauge, accessed on 4th January 2019.
- Mark Newton; http://www.jnsforum.com/community/topic/15147-understanding-japans-track-and-loading-gauges, accessed on 4th January 2019.
- https://archive.org/stream/railwaysornorai01fairgoog#page/n8/mode/2up, accessed on 2nd January 2019.
- Peter Semmens; High Speed in Japan: Shinkansen – The World’s Busiest High-speed Railway. Sheffield, UK: Platform 5 Publishing, 1997. p1.
- P.J.G. Ransom; Narrow Gauge Steam; Oxford Publishing Co., 1996, p107.
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- “Cultural, historical assessment of the Hex Pass Railway, Worcester to de Doorns”(PDF), accessed on 2nd January 2019.
- Jose Burman; Early Railways at the Cape, Cape Town: Human & Rousseau, 1984.
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- T.V. Bulpin; Natal and the Zulu Country (3rd ed.). Cape Town: T.V. Bulpin Publications Ltd., 1977. p224–227.
- https://wonderfulrife.blogspot.com/2013/10/gaijin-father-of-japans-railways.html?m=1, accessed on 5th January 2019.
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- Akira Saito; Why Did Japan Choose the 3’6″ Narrow Gauge? Japan Railway & Transport Review No. 31 (p33–38); http://www.ejrcf.or.jp/jrtr/jrtr31/f33_sai.html, accessed on 7th January 2019.
- Nobutaka Ike; The Pattern of Railway Development in Japan; in The Far Eastern Quarterly, Vol. 14, No. 2, February 1955; p222-223, sourced via https://www.jstor.org/stable/2941732?read-now=1&seq=6#page_scan_tab_contents, accessed on 8th January 2019.
- https://en.wikipedia.org/wiki/Yokkaichi_Asunarou_Railway_Utsube_Line, accessed on 8th January 2019; “The Yokkaichi Asunarou Railway Utsube Line (四日市あすなろう鉄道内部線 Yokkaichi Asunarō Tetsudō Utsube-sen) is a 762 mm (2 ft 6 in) narrow gauge railway line operated by the Japanese private railway company Yokkaichi Asunarou Railway, connecting Asunarou Yokkaichi Station and Utsube Station, both in the city of Yokkaichi, Mie, Japan.The line connects with the Kintetsu Nagoya Line and the Yunoyama Line at Asunarou Yokkaichi Station; these other lines use an elevated platform called Kintetsu Yokkaichi Station whereas the Utsube Line uses a low-level platform. At Hinaga Station, the line connects with the Yokkaichi Asunarou Railway Hachiōji Line, a one-station branch line. Because all trains on the Hachiōji Line offer direct service to Asunarou Yokkaichi via the Utsube Line, the two lines are collectively called the Utsube-Hachiōji Line (内部・八王子線 Utsube-Hachiōji-sen). … Until March 2015, the line was under control of Kintetsu, a major railway company.”
- http://www.kurotetu.co.jp/en/railway, accessed on 8th January 2019 and https://en.wikipedia.org/wiki/Kurobe_Gorge_Railway, accessed on 8th January 2019: “The Kurobe Gorge Railway (黒部峡谷鉄道株式会社 Kurobe Kyōkoku Tetsudō Kabushiki Kaisha), or Kurotetsu (黒鉄) for short, is a private, 762 mm (2 ft 6 in) narrow gauge railway company operating the Kurobe Gorge Main Line along the Kurobe River in the Kurobe gorge area of Toyama Prefecture, Japan. The railway was built to serve the construction of the Kurobe dam for the Kansai Electric Power Company, which was completed in 1963; Kurotetsu was spun off from the power company in June 1971, but remains a wholly owned subsidiary. At its terminus, the Main Line links to Kurobe Senyō Railway, which is not open to general public. … In 2008 the company operated 27 locomotives, 138 passenger carriages and 322 freight wagons.“
- https://en.wikipedia.org/wiki/Kiso_Forest_Railway, accessed on 8th January 2019: “The Kiso Forest Railway (木曽森林鉄道 Kiso-shinrin-tetsudō) was a network of 400 km of 762 mm (2 ft 6 in) narrow gauge light (keiben (軽便)) railway lines that operated in the Kiso Valley in Nagano Prefecture, Japan. … The railway was used to support the logging of cedar forests in the region. The Kiso Forest had historically been the possession of a local lord, but at the time of the Meiji Restoration had become the property of the Imperial family. In 1901, a railway was laid into the forests and was initially worked by hand or animals. The first 0-4-2T locomotives built by Baldwin Locomotive Works were introduced in 1907. Further locomotives were obtained from Baldwin, as well as a Shay locomotive that was transferred to the Alishan Forest Railway in Taiwan when that line opened. The railway was extensively rebuilt in 1920, with steel bridges and 24 tunnels. … The railway was abolished in stages between 1966 and 1976.“
- http://www.hrr.mlit.go.jp/tateyama/english/service/history.html, accessed on 8th Januaty 2019: “Tateyama Sabo’s service railway opened in 1926, and in 1929 11.7 km of track from Senjugahara to Kanbadaira went into operation. In 1965 the 18 km of railway to Mizutanidaira were completed. This section includes an 18-lebel switchback. At first the point switches were manually controlled, but between 1980 and 1986 they became entirely automated. However, for the sake of safety, an assistant driver checks that everything is running smoothly. The train has changed with the times up to the present day. This train, still today active in erosion control work, is one of the symbols of Tateyama Sabo.”
- Dan Free; Early Japanese Railways 1853-1914: Engineering Triumphs That Transformed Meiji-Era Japan; sourced via https://books.google.co.uk/books?id=MwbQAgAAQBAJ&pg=PT586&lpg=PT586&dq=Keiben+Railways+Japan&source=bl&ots=vp0hACPS5X&sig=CV5WU8ubrKhWLp3NAlgPuYyo454&hl=en&sa=X&ved=2ahUKEwiagIjig97fAhXTtXEKHTLhCv8Q6AEwC3oECAIQAQ#v=onepage&q=Keiben%20Railways%20Japan&f=false, accessed on 8th January 2019: “By 1910, when the desire to construct more railways [in Japan] was close to its peak, the cost of developing a railway to main line standards was likewise becoming more costly. As the framework of a national railway system was well underway, with most of the major trunk lines built and the few still needed under construction, most of the new lines projected were short local lines with modest traffic potential. In order to stimulate such lines, the government passed a Light Railway Law, which brought many keiben tetsud “light railways” into being. Within three years, the effect was notable. By 1913 the number of keiben tetsud had greatly increased, thanks to the simplified organizational procedures authorized by the new law and other governmental encouragements. As of that year, there were 38 keiben tetsud with 574 route miles in operation, an additional 44 with a route mileage of 800 miles under construction, and some 126 companies with a combined mileage of 1,953 miles which had received a preliminary charter, but which had not commenced construction. The law would be augmented in 1924 with the addition of a Tramway Law. In all, by the close of the Meiji period, there were approximately 208 such keiben tetsud contemplated to add some 3,328 route miles to the Japanese railway system. Many of the keiben tetsud were short, local affairs that acted as branch line extensions from the “main-line” grade shitetsu or IJGR, meandering along old cart tracts or the banks of local streams to bring rail transportation to small towns, remote locations, and otherwise un-served villages and hamlets of the hinterlands. They were often times on the shakiest of financial grounds, operating as it were “on a shoe-string” with second-hand, obsolete equipment purchased used from their more established “main-line” brethren if they happened to be of a matching gauge. Thus they often retained a quaint, nostalgic flavor, often all the more charming due to the hodgepodge of dated and mismatched equipment with which they were furnished.“
- By LERK, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=32955115
- https://www.trains-worldexpresses.com/500/519.htm, accessed om 8th January 2019.
- https://en.wikipedia.org/wiki/JNR_Class_C62#/media/File:C623_Express_Niseko.JPG, accessed on 8th January 2019.
- https://en.wikipedia.org/wiki/JNR_Class_EF62, accessed on 8th January 2019.
- https://en.wikipedia.org/wiki/JNR_Class_C10, accessed on 8th January 2019. NB: I have been informed that the note provided with this photograph is slightly misleading. The loco was built by Kawasaki. Kisha Seizo was a separate manufacturer.
- https://en.wikipedia.org/wiki/JNR_Class_C11, accessed on 8th January 2019. NB: Again the note provided with this photograph is slightly misleading. The loco C11 207 was built by Hitachi in 1941.
- https://en.wikipedia.org/wiki/Toei_Shinjuku_Line, accessed on 8th January 2019.
- https://en.wikipedia.org/wiki/T%C5%8Dky%C5%AB_Setagaya_Line, accessed on 9th January 2019.
- https://en.wikipedia.org/wiki/Toden_Arakawa_Line, accessed on 9th January 2019.
- https://en.wikipedia.org/wiki/Keio_Corporation, accessed on 9th January 2019.
- https://en.wikipedia.org/wiki/Hakodate_Transportation_Bureau, accessed on 9th January 2019.
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- Roar Stenersen; Development of Norwegian Railways, 1854-2002; Japan Railway and Transport TReview, June 2002, Volume No. 31, p39-41; http://www.ejrcf.or.jp/jrtr/jrtr31/pdf/f39_ste.pdf
- Akira Sato; Why did Japan Choose the 3′ 6″ Narrow Gauge; Japan Railway and Transport Review, June 2002, Volume No. 31, p33-38; http://www.ejrcf.or.jp/jrtr/jrtr31/pdf/f33_sai.pdf, accessed on 17th February 2019
- Takahiko Saito; Japanese Private Railway Companies and Their Business Diversification; Japan Railway and Transport Review, January 1997, Volume No. 10, p2-9; http://www.ejrcf.or.jp/jrtr/jrtr10/pdf/f02_sai.pdf, accessed on 17th February 2019.
Most common gauge for Indonesian Railways. The first railway was actually built to standard gauge (the Semarang – Solo – Yogyakarta corridor), but later lines were built to Cape Gauge size owing to economic feasibility. The remainder of standard gauge lines were regauged by Japanese army during WWII to 3 ft 6 in ( 1,067 mm ) gauge, with parts using standard gauge sleepers.