One of the best known of these was the survey conducted by Holt S. Hallett, a British colonial administrator, whose object was to promote a railway line to take British goods from the Gulf of Martaban (Burma), through what was then Siam, to Southern China. His superb book: A Thousand Miles on an Elephant in the Shan States, first published in 1890 and still an excellent source of information on Northern Thailand, was the main result of this journey: the railway, alas, was never constructed.
Then in 1887-1888, Messrs Punchard and Co., British Railway Contractors, were commissioned by the Siamese government, to survey a line from Bangkok to Ayutthaya and then to Korat, the first section of the current North Eastern Line. James McCarthy, a British engineer employed by the government of Siam, describes some of this work in his book Surveying and Exploring in Siam, first published in 1900.
A second line was to go from Ayutthaya to Lopburi, then on to Lampang, Lamphun and Chiang Mai. From Chiang Mai it was projected to go north to Chiang Rai and eventually to Chiang Saen on the Mae Khong (Mekong river).
Much of this survey bore fruit, some years later, in the construction of parts of the northern and north-eastern lines though the section of the northern line beyond Chiang Mai has not been constructed, even to this day: the connection north to China via Chiang Saen and the Mae Khong, was very attractive from a trade point of view, but the engineering difficulties presented by the mountains of northern Thailand proved too daunting.
A recent (March 2010) proposal from the Chinese Government, however, for a high speed link between Asia and Europe might at last result the long overdue rail link from Thailand to Southern China.
According to Antonio, the first railway in Thailand was the Paknam railway; the accompanying map shows this line following the course of the present-day Rama IV road, from near Bangkok Central Station eastwards towards the mouth of the river. This line, opened in 1893, is no longer in existence, though Thai friends remember using it in the 1950's.
Modern maps of greater Bangkok still show a Thanon Tang Rotfai Kao sai Paknam ("Road on the route of the former Paknam railway") from Khlong Toey eastwards towards the river mouth.
Rail Services to Ayutthaya opened on March 9th 1894, extending to Korat in 1900 as the first section of what is now the Northeastern line. A branch line to Lopburi became the first section of the Northern line to Chiang Mai.
In 1903 a line opened to Petchaburi on the west coast of the gulf of Siam. This eventually became the Southern line to Butterworth, Malaysia. At that time the line commenced at the Thonburi Railway station, now retired, originally in . Another line was under planning to Sri Ratcha on the east coast of the gulf of Siam (present day Eastern Line).
Antonio also mentions the construction of a private line from Thonburi to Tha Chin on the coast. This must be the Mae Khlong-Mahachai railway, now part of the State Railway of Thailand, though it does not connect with the main network.
This line is mainly used to ferry sea produce and passengers from the coast to Bangkok, but also provides the opportunity for a cheap and pleasant 1 day excursion from Bangkok to the old fishing ports of Samut Sakhon and Samut Songkhram: see the page Mahachai Railway.
Originally the Northern and Eastern Railways were controlled by the Northern Railway Authority, whereas services West of the Chao Phraya River (i.e. originating in Thonburi, West Bangkok), operated under a different authority - the Southern Railway Authority, and while the Northern Railway used Standard Gauge (1.435m - 4ft 81/2 inches), the Southern Railway adopted Narrow Gauge (1 meter), allowing it to link up eventually with the Narrow Gauge lines of British Malaya.
In 1917, The two authorities were merged as the Royal State Railways of Siam, and in 1920 Narrow Gauge, for logistical reasons, was adopted as the national standard. Conversion work started by adding a third line to the Northern network so that it could run Standard and Narrow Gauge trains. Conversion of the network was completed in 1930.
Before the two authorities were maerged the Northern and North-Eastern networks had been designed and run by German engineers, the Southern Line by British engineers. Once the two authorities were merged it was reasonably easy to run the two networks as separate enterprises, as at no point did the networks connect. This all changed with the decision to Bridge the Chao Phraya river at Bang Sue so that the Southern line could join up with the other networks. This meant that international traffic would be able to begin and terminate at Hua Lamphong Station in Central Bangkok, rather than on the other side of the River at Thonburi Station, which involved passengers in a rver crossing prior to departure. The Rama VI rail bridge, completed in 1927, was one of the first bridges accross the Chao Phraya river.