sign in a cave in Laos

16 October 2009

3D laser scanning of caves in Lenggong

The 3D mapping of caves with laser scanners has been tried in England and other European countries over the past decade, but has never really caught on. The best use for it seems to be to determine the size (volume) of large chambers. And for a 3D tour through caves for armchair cavers!

In Oct 2009 I was invited to join a group from UTM who were trying out a scanner in caves in Lenggong in Perak. None of the team were familiar with caves. Their idea is to scan caves "to generate a hyperaccurate 3D maps with 2mm resolution within a 25m radius. It can effectively scan every aspect of the cave including its speleobiology". I really have my doubts about the latter claim. They then suggested it could help bat researchers to identify species. However I think this is not very practical, and certainly not down to species level, and bats would still have to be caught and identified, or else bat detectors used. Although the claim is it can detect anything above 6mm in its 120m range, and 2mm in a 25mm range, this certainly won't show bat species, and definitely not the smaller cave creatures.

One problem is transportation, as the scanner in its box weighs about 24 kg and out of the box about 14 kg. It comes in 4 sections. It's easy enough to scan in a chamber with a single set-up for the laser scanner, but would become very tedious in a cave passage needing multiple set-ups.
booting up the computer
placing the markers
Carrying the equipment and setting it up in the next cave -
placing the markers again

The bats

Looking at the results

I took some info from the Faro www, Faro is the maker of the scanner.

FARO Laser Scanner LS

With the Laser Scanner LS, FARO offers a 3D measurement device, capable to capture large volumes within a very short time.
Captures 3D environment in a highly precise way.
Measuring procedure begins in the laser unit. A rotating mirror directs the laser beam into the area of measurement. Distances determined by the phase shift of the reflected laser beam opposite the transmisison beam. With the help of the angle of the rotating mirror and the angle of the laser scanner, the module calculates the coordinate and stores the data. Procedure is repeated several hundred thousand times per second.

In May 2010 new items reported on scanning the Nottingham Caves in UK, and gave some useful information on the scanning.
See 3D scanning Wang Burma.

© Liz Price
No reproduction without permission

13 October 2009

3D mapping Wang Burma

In Oct 2009 I joined these guys from UTM to laser scan 2 caves in Lenggong in Perak.

12 October 2009

Sifu & Tongga - Gua Kajang


In October 2009 I revisited Gua Kajang at Lenggong in Perak. I was surprised to find a tarred road now leads right to the cave overhang. I was told that a Malay film, Sifu dan Tongga had been filmed there last year.

Here's a 10 minute clip of the film, the middle parts show some interesting cave scenes.

Unfortunately the crew didn't think to remove their bamboo platforms and bamboo torches after they'd finished, so they are still littering the cave.

4 October 2009

Mun Fatt Ngam & Stairway Cave, Gunung Mesah, Perak

I don't often post albums on individual caves, but as Waterfall Jan asked me about this one, which is of historical interest, I thought I would share it.

Mun Fatt Ngam, also called Cave of the Thousand Buddhas is in Gunung Mesah, just south of the Gopeng toll interchange, off the old trunk road, south of Ipoh, in Perak. I first went to the cave in 1994 and had forgotten about it. I remember on that visit we had trouble finding the cave. So this time, Sept 2009, I was surprised when the road ended at a prawn fishing pond.

A man working there guided us to the base of the stairs behind the pond and we began the long climb.
There are about 400 steps up the hill - I roughly counted 380 on the descent, but at the bottom there are no steps, they have disappeared over the years. The handrails are completely broken.

About 3/4 of the way up we saw a small cave on the left, so went in and surveyed it, and I named it Stairway Cave as its not in my Cave Register. It is only a small cave but has some interesting geological aspects.
Surveying Stairway Cave -
centre rocks cemented by mud
entrance wall Stairway Cave

Some monsoon rain meant we had to take shelter for a while before continuing to the top of the stairs.
pillar supporting stairs
We came out into a nice overgrown "garden" in front of the large entrance to Mun Fatt Ngam.
Nice garden
The entrance is impressive because of the white rock and the fluting (long grooves in a cave wall). The entrance is actually quite similiar to Gua Kanthan with its large size and also the fluting.
Looking out -

Mun Fatt Ngam consists of just a single chamber, approximately 150m long and 40m wide (we surveyed the cave but I don't have the figures yet). Apparently the cave was known in the 1880s - it was said to have been discovered before the founding of Kampar in 1886. It was used as a Taoist temple, and had its heyday during the days of tin mining.
Remains of a pillar

Inside a few altars have been made in front of natural stalagmites, but there are no longer any signs of the Buddhas.

There are several water tanks and the remains of wooden posts which may have been some form of pulley or maybe lighting. Apparently there used to be a pulley up the hill to hoist up supplies. At the entrance to the cave is a kitchen, with a stove to take 2 woks.
I was surprised there was no sign of soot on the stove, although the cave roof above was completely black. Several nails had been cemented into the cave wall to use as hooks.
The descent -
start of the stairs

The temple was abandoned in 1969 after the Communist troubles. Mun Fatt Ngam should be treated as a heritage site as it is linked with the Chinese immigration into Malaya, as well as being an impressive cave.
Gunung Mesah from trunk road

See video taken by Jeroen.

© Liz Price
No reproduction without permission

3 October 2009

dubious bridge near Tempurung

In March 2004 when trying to reach some caves on Gunung Gajah, south of Ipoh in Perak, we came to this old wooden bridge. My 3 pasengers chickened out and got out of the car and walked across, using the excuse that they were checking the bridge for me to drive over.

In Sept 2009 I found myself going back to the same caves. Having told my passenger about the old wooden bridge, I was surprised when we reached this "new" concrete bridge. I wondered why the ramp on the bridge was so steep, and my passenger got out to check I wouldn't ground the car. It was only when I'd driven across and reached the flat part again, that I got out to look......... and realised just how damaged the bridge is!
Wooden bridge 2004
Concrete bridge 2009 -
Bridge on Google Earth

Just across (east) of the bridge is a scenic lake, so it makes the crossing worthwhile. The lake is quite big as can be seen on the GE photo.

© Liz Price
No reproduction without permission