200-Meter Tunnel Discovered in Sri Lankan Prison


In a startling discovery, officials of the Kalutara Prison on Horana Road have found a tunnel nearly 200 metres long and eight feet below the prison ground leading to the Kalu Ganga complete with electricity and light bulbs, dug by LTTE suspects in custody over a period of one year.

The tunnel was uncompleted. And the article fails to answer the most important question about this sort of thing: What did they do with the dirt?

“We also suspect that they would have daubed their bodies with soil and had later washed it away to prevent detection of their clandestine project,” the official said.

I don’t see that method being able to dispose of 200 meters worth of dirt over the course of a year, even assuming a small tunnel.

Posted on October 5, 2007 at 1:47 PM25 Comments


Michael Ash October 5, 2007 2:19 PM

Really rough: assuming 2m^2 surface area per human, 1mm of dirt spread evenly over the skin, and a 1m^2 cross section tunnel, done once per day for a year, you get a length of 73 centimeters. In order for that to create a 200 meter tunnel you’d need almost 300 people working on it daily. That does sound pretty unlikely.

Dom De Vitto October 5, 2007 2:39 PM

Wires and Lights? The Boston Police Department would have never allowed such things….

I guess you could stick it in your pockets, and throw it into the latrine/toilet. Don’t think the guards would check that too carefully.

An impressive group effort.


Garick October 5, 2007 4:00 PM

I suppose you could hope most of it blows away …. 1 meter diameter hole 200m …
is 628000 liters of dirt.

which would be 9 inches deep over a square mile.

if it was a little at a time perhaps it would blow away outside.

if 1720 prisoners flushed a liter of dirt down the toilet every day it would take a year.

This is astounding.

Where did the dirt go.

Dale October 5, 2007 4:19 PM

From The Great Escape:


Three tunnels were dug, shored up and lit much as portrayed in the film. One of them was discovered by the Germans just as it was on the verge of completion. Sand from the tunnels was put in bags which were hidden in the prisoners’ trousers. The prisoners would wander around the camp and pins sealing the bags would be released, spreading the dirt over the compound. The men doing this job were known as “penguins”.

Gross October 5, 2007 4:44 PM

Have you considered the possibility that they ate the dirt and left the rest to mother nature?

Curious+Lazy October 5, 2007 4:46 PM

Well, the article stated the following:

“Authorities had found some fifteen gunny bags filled with soil near the toilet pit.”

And Wikipedia says:

“A gunny sack holds approximately 100 pounds of potatoes”

I’m far too lazy to do any math here, but seems like at least a fair portion of the dirt could be accounted for?

Tom October 5, 2007 6:42 PM

If the soil is sufficiently porus, they could have simply pushed it out of the way. I kinda doubt it would have been, though.

Lollardfish October 5, 2007 7:27 PM

Pradeep’s idea – bribery – seems much more likely than anything nifty and clever. It goes back to Bruce’s oft-repeated comments about trusted insiders.

Neighborcat October 5, 2007 8:53 PM

Toilets aren’t magic, the stuff you flush has to go somewhere, and mud isn’t really compatible with sewer pipes. It tends to settle out and plug things up.

Then there is the problem of water usage. Presumably the prisoners still had to use their toilets for their intended purpose, so I suspect the management would notice a several-fold increase in water usage.

I vote for bribery, but what could guards even do with it? They would have to carry it out of the compound somehow.

“Honey, why is your lunch-box full of dirt again?”

Freiheit October 5, 2007 9:47 PM

@Garick and Merlin

Quit changing from metric to standard! It confused me to the point that I had to solve this myself in both systems.

Assume a cylinder with a 1 meter diameter and 200 meters long. V = pir^2h.

pi.5^2200 =~ 157 cubic meters.

Spread over a square kilometer (ie 1000 meters on a side) we get 157 / 1000*1000 = 0.000157 meters thick. Thats 0.157 millimeters.


Assume a cylinder with a 3 foot diameter and 600 feet long

V = pir^2h.

pi1.5^2600 = 4239 cubic feet

Spread over a square mile (5280 feet on a side) that would be 4239 / (5280*5280) = 0.000152053 feet thick. Converted to inches we get 0.001824638 .

At those thicknesses it’d be barely noticeable (even accounting for the rounding errors) unless the soil they were digging through was drastically different in color or texture than the surface soil. I know in the mid-US that may be an issue, not sure about an island though.

If anyone would care to convert that to Libraries of Congress and Olympic Sized swimming pools that’d be great.

janantha October 5, 2007 9:48 PM

When i first saw this on tv I was thinking if Micheal Scofield was there! It may be an exact redo of Prison Break.. The dirt may be carried by individuals on their pockets. In Sri Lanka u can bribe your way into getting a mobile phone. So im guessing the actual Tunnel making project may be an idea from an outsider.. It must have taken a very long time for them to dig the whole thing up.

Wil October 7, 2007 4:13 PM

“So im guessing the actual Tunnel making project may be an idea from an outsider..”

if outsiders are involved, why not start the tunnel from outside?

anonymous October 9, 2007 1:07 PM


Unfortunately google’s unit conversion doesn’t recognize “olympic pool”, but they are minimally 2.5 million liters. So they dug out about 1/15th of a pool.

Hey I can finally meaningfully ask google what “26 fortnights per furlong” is!

How big is the library of congress (on any given day) anyway?

No wonder the prisoners protested being transferred to another prison.

bob October 10, 2007 8:00 AM

Wow they had light bulbs AND electricity. I could easily see one or the other, but both at the same time – thats something. Wouldnt light bulbs pretty much imply electricity? Unless they wanted to show what a lame effort it was or that they were fighter pilots who expect light bulbs to just work without any wires or power source.

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