4) The archaeological excavation at the fortress of Krom
Phrarajawanglang palace in the AREA 3
AREA 3 was located at the back of the former Thonburi train
station building. The first excavation of this area occurred in 2008 and
was worked on further in 2011-2012. According to the archaeological
excavation, ruins measuring 18 meters was found. From the position
and direction of the brick depth, it could be equivalent to the row of the
fortress of Krom Phrarajawanglang palace that appeared in an ancient
map of Bangkok in 1896. Therefore, we know that this brick row had
once been one part of the fortress palace constructed in the reign of King Rama I. Prince Damrong Rajanubhab composed a title about the
fortress of Krom Phrarajawanglang palace such that “the fortress of
Krom Phrarajawanglang palace was constructed at Suanlinchi Sub
district (the current location of Siriraj Hospital) since Krom Prarat
Wang Lang was promoted to Somdet Prajaolarnter Jaofah Krom Luang
Anurak Thewet. The fort was built at such area since the Thonburi period
so it was important to prevent the west of the city to the fortress palace”
(1970: 11). From such historical evidence, we know that this brick row
of the fortress palace had once been the northeast fort of Thonburi city.
Then, it was changed to the northeast fort of the fortress palace in the
reign of King Rama I.
According to the archaeological excavation of the fortress palace,
it was found that the brick row constructed as the wall of the fortress
palace might have been a part of the wall of the Thonburi fort. It was
found beneath the current ground surface at a depth of 1 meter, the width
of the wall was about 1.9-2 meters, the average dimension of bricks was
(W) 17.5x (L)34x (H)8.5 cm. The brick surface appeared to have a lot of
traces of chaffs as one of the burnt raw materials. The height of the brick
row was about 2.3 meters. The bricks at the bottom were bigger than
at the top; counting from the top until the 6th layer was at an average of
(W)17.5x (L)34x (H)8.5 cm. On the other hand, the 6th-8th layers were
thicker than others with the average sizes of (W)17.5x (L)34x (H)10 cm
and the 9th-19th layers were bigger than other layers with the average sizes
of (W)18.5x (L) 36x (H)14.5 cm. The wall row of the fortress palace was
constructed by using bricks for bearing the whole weight of the fort and
logs or other items had not been found for load bearing. According to
the excavation of the lowest level, it was found that under the last brick
row (the 19th layer) sand was used with the same size as selected from
other areas for improving the area intentionally before the pedestals with
bricks were constructed. The age determination of the brick samples
carried out by using Thermo luminescence dating demonstrated 523±
years or B.E. 2032±40. (The results are from the brick analysis with
Thermo luminescence dating technique, Department of Earth Science, Faculty of Science, Kasertsart University)
Besides the ruins of the wall of the fortress palace, the ruins of
the sidewalk around the fort was also found at a depth of about 100-120
cm from the current ground surface, the width of the bricks was about
1-1.20 meters with the average size of (W)18x (L)36x (H)12 cm. The
surface of the bricks had traces of lot of chaffs. These bricks had holes
and most of them had 3 holes. The discipline for laying had the specific
system of using the two bricks for the reversed long and short range
respectively. Based on the excavation in detail, it was found that the
row of the sidewalk around the fort was constructed to cover another
layer of the sidewalk. It was constructed by using smaller bricks with
the average size of (W) 14x (L)26x (H)4.5 cm. Most bricks were broken
as a half.
It can be concluded that the ruins found at the back of the
former Thonburi train station building was the fortress of Krom
Phrarajawanglang palace, which was located at the north east corner of
the fortress palace in the reign of King Rama I and might have been a
part of ancient wall of Thonburi city in the Thonburi period.