London Rejects Subway Scanners

Rare outbreak of security common sense in London:

London Underground is likely to reject the use of passenger scanners designed to detect weapons or explosives as they are “not practical”, a security chief for the capital’s transport authority said on 14 March 2006.


“Basically, what we know is that it’s not practical,” he told Government Computing News. “People use the tube for speed and are concerned with journey time. It would just be too time consuming. Secondly, there’s just not enough space to put this kind of equipment in.”

“Finally there’s also the risk that you actually create another target with people queuing up and congregating at the screening points.”

Posted on March 23, 2006 at 1:39 PM19 Comments


Bryan March 23, 2006 2:02 PM

I was just reading your airport screening post, but now you give me this, so I’ll just comment on both…

It appears to me that those in charge seem to think bigger locks are what we need. They completely forget the old adage that says “build a better lock, get better criminals”. It seems counterproductive to security to always beef things up when there is little improvement in our actual security levels.

I feel just as safe today at the airport as I did pre-9/11.

Eric K. March 23, 2006 2:19 PM

You feel that safe? Wow.

Before 9/11, I didn’t worry about terrorists.

After 9/11, I still don’t worry about terrorists…unless you’re referring to the TSA. Is it not their job to terrorize American travellers?

Anonymous March 23, 2006 2:23 PM

Actually, the last point is interesting. I wonder what the reaction would be if terrorists blew up the line waiting for airport security…

Chris Brew March 23, 2006 2:30 PM

Britain has career civil servants whose jobs do not (directly) depend on which politicians are in power. Many of these people actually use the Underground, so they have a stronger interest in keeping it running sensibly than in making expensive and futile gestures in the name of security. Whereas, in the US, …

Richard Braakman March 23, 2006 3:12 PM

@Eric K: I have that too. The security guards make me more nervous than the remote possibility of an attack on my flight.

roy March 23, 2006 4:08 PM

“I wonder what the reaction would be if terrorists blew up the line waiting for airport security…”

My bet is DHS would announce an immediate ‘national ground stop’, grounding all flights, with those airborne to land at the nearest airport, and then suspending all civil aviation (with exceptions for important people) while the media churned up the terror angle and the government’s decisive responses.

The airlines and their dependent industries would lobby hard for another ‘one time bailout’.

Eventually the sense of panic would wear thin and the business would start ramping up stagewise.

I’m sure DHS would add ‘additional layers of security’, such as outer choke points to concentrate the crowds, just like before, but moreso, effectively increasing the number of massed-people vulnerable areas.

What would be missing would be the obvious point that DHS created the exploited vulnerability, making a choke point where there should be a smooth flow.

Ian March 23, 2006 4:13 PM


Their aim is not to protect the public, their aim is to protect their own public image. What’s a better sound bite (the de facto ultimate form of political message):

“We’re perfectly safe and all that other stuff is just a waste of time, money and manpower.”


“I will create new SuperScanners that will catch all the terrorists that would try to kill you, rape your wife, and feed your children to your dog.”

Anon Y Mouse March 23, 2006 10:26 PM

I’ve heard stories that some number of the New York City subway turnstiles have some sort of radiation detectors built in and that people with radioactive pellets implanted as part of prostate cancer treatment have occasionally been approached by cops after setting off a silent alarm.

Perhaps the technology for bomb sniffing will improve to allow that sort of screening rather than the slow metal detector lines at airports and various other public entrances.

jmm March 24, 2006 3:24 AM

Interestingly, the article doesn’t mention the only time scanners /would/ be reasonable — when they can be highly accurate and take no more time then it takes someone to walk through the ticket barrier. That is, you put in your ticket, it validates the ticket is valid, scans you, and lets you through if all is good, without taking significantly more time then it takes to just validate the ticket’s validity and walk two steps.
AFAIK, this leaves out most sorts of testing in current use /with the exception of explosives sniffing/, which AFAIK doesn’t take all that long. OTOH, I don’t know about it’s error rate.

Tim March 24, 2006 3:37 AM


Most travel on the Underground nowadays is conducted using RFID ‘Oystercards’. You spend literally two seconds going through the ticket barrier. I highly doubt they’d be able to scan anybody that quickly, especially as you don’t have to stop walking as you pass through.

arl March 24, 2006 7:07 AM

Good common sense on the comment on attacking the queues. Anyone paying any attention to the suicide attacks in Israel would notice how often that went on.

Leo March 24, 2006 8:24 AM

I have seen Transport for London staff purposely routing people through open gates (thus defeating Oyster card readers) in an attempt to expedite flow at peak times. This implies that the ingress-egress points are running very near its capacity, and thus can be overwhelmed quite easily by usage bursts. Even marginally increasing the time a user spends in the gate could lead to congestion.


What would the scanner do in case of a positive? The usual result when a gate does not open when presented with an oyster card is the user slamming into it, with the user behind slamming into him/her, and so on. Users start diverting to neighbouring gates, which in turn start becoming bottlenecks. With that amount of people clustered around the blocked gate, detonating the bomb on the spot could very well be as effective as doing it on a train.

shoobe01 March 24, 2006 1:58 PM

“Actually, the last point is interesting. I wonder what the reaction would be if terrorists blew up the line waiting for airport security…”

One of the more horrible terror attacks I recall was:

“December 27, 1985: Four gunmen belonging to the Abu Nidal Organization attacked the El Al and Trans World Airlines ticket counters at Rome’s Leonardo da Vinci Airport with grenades and automatic rifles. Thirteen persons were killed and 75 were wounded before Italian police and Israeli security guards killed three of the gunmen and captured the fourth. Three more Abu Nidal gunmen attacked the El Al ticket counter at Vienna’s Schwechat Airport, killing three persons and wounding 30. Austrian police killed one of the gunmen and captured the others.”

Yes, there was terrorism before the US got attacked on our own soil. We do a good job of forgetting all these lessons from the past though.

“December 17, 1973: Five terrorists pulled weapons from their luggage in the terminal lounge at the Rome airport, killing two persons. They then attacked a Pan American 707 bound for Beirut and Tehran, destroying it with incendiary grenades and killing 29 persons, including 4 senior Moroccan officials and 14 American employees of ARAMCO. They then herded 5 Italian hostages into a Lufthansa airliner and killed an Italian customs agent as he tried to escape, after which they forced the pilot to fly to Beirut…”

Who doesn’t think that a brute-force attack in the airport (pre-security) in the US today couldn’t lead to control of one or several aircraft?

Tom Chiverton March 26, 2006 11:02 AM

nsfw ?
Let us know where you work so we can make sure we never share an office 🙂

Haninah March 26, 2006 6:31 PM

@ Anonymous and the whole attacking-the-line-in-front-of-security thread

You are all correct that this is a serious concern in Israel. At particularly busy malls etc. there is a separate barrier around the area where the line forms to go through the security screening, with armed guards (actually more heavily armed than the ones doing the actual screening) eyeballing the crowd as they enter that enclosure as a sort of zeroth-order security check. At Ben Gurion airport, they go even further, and have a preliminary inspection of all vehicles, including public buses, as they enter the airport grounds.
These safeguards are highly effective, as demonstrated by the fact that to date the airport has not been attacked, and the attacks which have taken place on lines outside public venues have tended to have very few casualties, often only the attacker and the security guard. They are pretty heavy-handed, though, and are not really recommended for any society that isn’t actually under attack.

Clive Robinson March 27, 2006 9:58 AM


“These safeguards are highly effective, as demonstrated by the fact that to date the airport has not been attacked”

Wrong conclusion from the evidence. The only conclusion you can draw is “I am unaware of any attacks”.

I suspect that if ANY airport was examined correctly it would have a huge number of security flaws that could be exploited with great success. The fact that it has not yet happened in no way proves an airport (or anywhere else for that matter) secure.

For instance my local airfield (privatly owned flying club) has never had a terorist attack against it. However as it only has a three strand barbed wire fence around most of the perimiter, I have the feeling that it could be attacked if a terorist had reason to. In fact it has had a vandalisum attack which gives rise to the question “Has there been any vandalisum At Ben Gurion airport?” (to which I allready know the answer is yes).

Terorists generally attack week vunerable spots with high (to them) asset value. The fact that what is an is not a week target is sometimes difficult to judge (9/11) prior to an attack does not make it secure.

DigiLife March 29, 2006 5:13 PM

10 years of airport security with no attacks before/until 911. was the security good and just eventually circumvented? was it bad but just unneeded cuz it was never taken advantage of before? i know one thing: you won’t get a warning of when you will need the security or know how good the security will need to be until after the fact. hindsight is 20/20 or better.

i know something else. when the most desirable targets become “secure enough” (literally), the terrorists will start planning against the less secure second-most desirable targets. and so on, and so on…..

when i talk to computer security experts i get the same story. no such thing as a “perfectly” secure machine. when i talk to personal security experts i get the same story. if he wants to kill you badly enough, there’s nothing that can stop him, sooner or later he will succeed. terrorists work like computer tiger teams, tricking people to test security barriers to test them. then work out a way to make a full scale attack like 911 work. it took them 2 years in the case of 911. that’s not barbaric blind brutality. that’s intelligent planning. something i’ve yet to hear the U.S. Government admit to. if that’s the case, no amount of “security” will ever be enough.

we are told that the price of freedom is eternal vigilance. having a few people watch over everyone else looking for the few terrorists among the sheep so far hasn’t really worked anywhere that i know of. perhaps we would all be safer if we adopted a different model where we all keep on the lookout (like a herd of elephants). the biggest problem with that model is already evident. some people doing the looking are just plain idiots when it comes to security. over-reacting and under-reacting. you can believe the terrorists will not educate us on how much response would be perfect and correct. and you can believe the perfect and correct amount/type of response will be different every time.

i don’t see a real solution to this anytime soon. obviously people need to recognize the threat and the appropriate responses. of course any education the people get, the terrorists will get too. we need an open source solution. a safe that’s still secure when the enemy has the blueprints, a hundred safes to play with, and a key to one of them.

consider also: a knife is taken on a plane. the person carrying it, gets off the plane at it’s destination and takes a taxi out of the airport having not used the knife since he packed it. an second person takes a knife on a plane. mid-flight the person approaches the flight cabin with the knife. the person pulls the knife out and begins to pick the lock to the flight deck door (where the pilot, etc. control the plane). an air marshal puts a gun to the persons head. the person is arrested after the plane lands. after 911 we secured the airports. me…..i dunno, i might’ve secured the planes. are we attacking the problems correctly?

seems to me that a few terrorists on a plane can be sensibly handled with an air marshall or 2. a plane full of terrorists isn’t worth saving. we need to do some serious and sensible rethinking of how we go about solving security problems and “dangerous situations” today.

Leave a comment


Allowed HTML <a href="URL"> • <em> <cite> <i> • <strong> <b> • <sub> <sup> • <ul> <ol> <li> • <blockquote> <pre> Markdown Extra syntax via

Sidebar photo of Bruce Schneier by Joe MacInnis.