Nong Pladuk is the true start point of the TBR. The existing rails at the time came due west from Bangkok and took a hard left turn to the south running through the small town of Ban Pong. The TBR takes a hard right after Nang Pladuk (actually near downtown BanPong) and runs an extremely straight path up to Kanchanaburi — about 50Kms.
The TBR at BanPong
One of the things I find fascinating about the TBR is why the IJA Engineers chose the precise route they did to lay the tracks. For example, IJA Railway Engineer Officer Futamatsu tells us in his book Across the Three Pagodas Pass why the bridges were built at Tamarkan just beyond the old city of Kanchanaburi rather than crossing the river between Tha Muang and Kanchanaburi thereby making the route shorter: stability of the river bed.
But in studying the map at NongPlaDuc I noticed something rather odd there too. In the 1940s, a single rail line ran from Bangkok to the existing railyard at NongPlaDuc. There is a marker at that station, placed by the IJA, that denotes the start point of the TBR. Just west of NongPlaDuc the existing rail line turned south to the isthmus and on to Singapore. To get to Kanchanaburi the rails needed to go northwest.
But rather than make a simple right turn upon exiting NongPlaDuc, they built a parallel track straight west into BanPong. After about 3.5 Kilometers, that second rail makes two right turns and heads NW directly (straight as an arrow) to Kanchanaburi. Why then did they feel a need to make what is essentially a sweeping turn running through the town of BanPong and bring the tracks into and out as opposed to a right turn just past NongPlaDuc?
The terrain from BanPong and essentially from NongPlaDuc to Kanchanaburi was essentially flat and un-obstructed. We do know that the reason why the rails run from the Kanchanaburi river crossing all the way back to ChungKai before they turned west again was that there was a hill of sufficient grade as to present an obstacle to the locomotives of the era pulling a fully loaded train over it. It was deemed easier to chop through the two limestone outcroppings on the river bank than build over Khao Poon. Perhaps though, there were enough slight hills or rises between NongPlaDuc and Kanchanaburi that the engineers wanted to take the rails closer to the Mae Klong River before aiming them at Kanchanaburi.
Below are some photos of the rather nondescript tracks as they split off from the parallel tack running into BanPong and make two curves aiming them towards Kanchanaburi.
Until quite recently, it was very unusual for there to be a double-track on any part of the Thai Railway System; except of course at some stations and repair and maintenance yards. So why in 1942, did the IJA Engineers decide to build a parallel track looping through the town of BanPong?
Even today, Nong Pladuk is a active station but serves mainly a repair and maintenance facility. The POW camp was located just to the north of the rails.
The POW map to the Nong Pladuk cemetery suggests that it currently lies under the sugar cane field just to the northeast of the current Station house.
B-29s bomb the NongPlaDuc Rail yards