by Geoff T.

How the perpetrators of the 7/7 event carried out the explosions on the three tube trains has always been a subject of some debate, and so, here, I would like to offer my own “penny-worth” of thoughts.

It is generally known that an Israeli/Mossad company was responsible for security on the London Underground back in 2005, which could well mean that the perps. had inside assistance in gaining access to the tube network in the days leading up to the attacks. In fact, without this “insider” help the event could not have taken place at all.

So, my contention is that the devices were placed beneath the rail tracks, just inside the tunnels outside Aldgate and Edgware Road stations on the Circle Line, and some distance north of Russell Square on the Piccadilly Line. I don’t believe that that any bombs were planted on board the trains – either inside the carriages, or beneath the floors. The reason is, that the perps. could not guarantee that the three trains would be in the right positions, on the “correct” side of Kings Cross when the devices exploded. (This was absolutely essential for the “suicide bomber” story – if just one of the explosions had taken place before the trains had arrived at Kings Cross, then the prepared narrative would immediately collapse.)

We therefore have to work out how explosions which occured inside the carriages were caused by devices that were planted outside the trains. We also need to figure out how the detonations could have taken place almost simultaneously.

The first problem is trying to establish a method whereby an explosive device can somehow punch upwards through the solid steel understructure and metal alloy floors of a tube train carriage. Well, my thoughts initially turned to the military anti-tank weapons that have been used on battlefields ever since WW2. The shells are not very large, slender in diameter, and are built of toughened steel that can penetrate the thick armour of a tank – that’s if enough energy can be generated by the gun’s firing mechanism to create a high enough velocity. The shell itself is packed with high-explosive, and incorporates a delayed-action fuse which allows it to detonate inside the tank, and not immediately when it comes into contact with the outside of the hull. (On the battlefield these shells are fired at targets some distance away, so a long barrel is required for range and accuracy, but firing a shell from a railway track upwards into a train passing overhead will only need a barrel the length of the shell itself.)

But moving on from this, I turned to Wikipedia and found an interesting article entitled ‘Rail Gun’. And it describes a Rail Gun as;-

“an electrically powered electromagnetic projectile launcher… comprising a pair of parallel conducting rails, along which a sliding armature is accelerated by the electromagnetic effects of a current that flows down one rail, into the armature, and then back along the other rail.”

“the armature may be an integral part of the projectile, but it may also be configured to accelerate a separate, electrically isolated or non-conducting projectile.

“a Rail Gun requires a pulsed, direct current power supply. For potential military applications, Rail Guns… can achieve much greater muzzle velocities than guns powered by conventional chemical propellants. Increased muzzle velocities [gives] increased terminal velocities, which can allow the use of Kinetic Energy rounds as a replacement for explosive shells.”

So, this modern weapon system can dispense with traditional high-explosive shells and replace them with “Kinetic Energy rounds” – very interesting indeed ! – as is the claim that a Rail Gun requires a Direct Current power source.

Now, the London Underground – or at least the Circle Line and Piccadilly Line back in 2005 – were indeed powered by Direct Current (or DC electricity). The main power supply from the National Grid arrives in the tube network by means of high voltage Alternating Current (AC), but this is converted into DC at a much lower voltage at a series of ‘feeder stations’ that stand alongside the track inside the tunnels. This Direct Current is then fed into the ‘live’ rail that provides power to operate the train motors – or ‘traction’ as it is called.

But the Underground also incorporates a ‘fourth’ rail, which ( in addition to the two ‘running’ rails on which the train wheels run ) carries the returning current back to the feeder station. The ‘live’ rail – from which the trains pick up the electric current through a collector shoe – carries +420 volts DC, while the ‘negative’ rail takes -210 volts. Together they combine to produce a 630 volt traction current ( source;- London Underground Power Supply System ).

The question is – is it possible that some kind of ‘Rail Gun’ was used on 7/7? Were such devices, that combined an armature with a launcher, buried beneath the tracks between the two electric current rails ? Could a powerful electromagnetic field be created, strong enough to launch ‘Kinetic Energy rounds’ up into a tube train carriage ? Maybe the armature used in these incidents was not a ‘sliding’ or moveable device, but a static one.

Part 2: a possible scenario for what took place in the days leading up to July 7th 2005.

Very early on the morning of Tuesday 5th July – just two days before 7/7 – the tube network shuts down at its normal time, just before 1 am. The “insider” personnel who work within LU Security then take charge of the section of Circle Line around Edgware Road. They make sure that the station and track is clear of any maintenance workers, cleaners or other staff who are not part of the plot. All CCTV cameras are switched off.

Meanwhile, during the weeks prior to this, the perpetrators have assembled a small team of maybe six operatives with two large transit vans. In addition to the drivers – who will stay with the vehicles above ground – the other four guys form the group who will go down into the tunnel to lay the explosive device on the track. One guy is an electrician, a second man is the explosives expert, and the other two are general handymen who are needed for the heavy work – carrying the equipment, cables, tools etc.

The transit vans arrive outside Edgware Road soon after 1am, and are met by a couple of “insiders” from LU Security who open the gates to allow the operatives into the station. (The presence of maintenance vans parked outside the partly-opened gates of a tube station in the early hours of the morning would not seem out of place, even to a passing police patrol – tube maintenance is a regular feature in central London during the hours when the system is closed.)

Having been supplied in advance with the plans of the track layout, and power supply diagrams for the Edgware Road sector, the team have already pre-selected the site where they want to place the device, and immediately start work. (Incidentally, the power supply on the tube is always switched off at night, so there is no danger of electrocution.)

Now, the track of the Circle Line consists of thick wooden sleepers that are embedded into ballast. The explosives expert chooses a spot on the track bed and asks one of the handymen to dig out all the ballast between two of the sleepers. Once this has been done the expert places the armature, along with its firing mechanism and launcher into the cleared area – and the ballast is then replaced and packed in all around it. This will hold the device firmly in place – preventing it from moving when it is fired. The projectile (a kinetic energy round ?) is loaded into the launcher. Everything is now hidden below the track so that train drivers will not see anything amiss in the next couple of days.

While this work is being done, the electrician fixes two “coupler-units” to the pair of adjacent electric current rails. These units are U-shaped and are clamped on to the sides, and underneath the rails (the top surface must be left clear for the power collector “shoes on each train to function normally. Short sections of thick cable are then connected from these coupler units to the armature of the explosive device.

After completing this, the electrician goes to work with a mechanical timer, an electronic sensor, a powerful battery, and a long length of flex. He connects the battery to the timer and sensor, and places all three items in a small area cleared of gravel, some 25 metres away in the direction from which the trains will come. He then runs the flex from them to the new coupler-units that he has just installed. These are equipped with switches that will automatically open as soon as an electric charge is generated by the sensor and battery.

The electrician now ensures that switches on the coupler units are closed, so that the normal current will continue to flow through the normal circuit when the power supply is switched on again. No one will then be any the wiser that the electrical system has been tampered with. The final act the electrician does is to switch the timer on and sets it for 08.49.00 on 07.07.

By 4.30am the team have finished their work at Edgware Road, cleared up their equipment, and left the station. The tube network is now ready to re-open as normal for that day’s travellers.

Next morning at 1am (Wednesday) they arrive at Russell Square to be met by the same security personnel, who open up the station.

Now, the track of the deep-level Piccadilly Line is rather different from the sub-surface Circle Line, as here all the rails sit upon small wooden blocks that are bolted into the concrete floor of the tunnel. But running along the entire length at the centre of the tunnel floor is a deep, narrow pit which acts as a drainage channel. This is often filled with ballast to help reduce train noise.

After arriving at their pre-selected site on the track, the team carry out exactly the same procedure as the night before, only this time the device is placed within the drainage pit, and ballast packed in either side.

On Thursday morning (7/7 itself), the scenario is repeated for the third time – back on the Circle Line just outside Aldgate Station. And by 4.30am the perpetrators work is all finished, and the team can now disperse – to await far away from central London for the devastating results which will occur just a few hours later.

Part 3: what may have happened on that fatal morning.

On the morning of 7/7 the Underground network opens as normal, and the rush hour gets under way. At exactly 08.49.00 the timers in the three separate tunnels energise the batteries, which in turn activate the electronic sensors. These are then able to register the arrival of the very next train to pass overhead. And when it does, the sensor sends an electric signal back through the flex to the automatic switches on the coupler units attached to the current rails. These switches immediately open, causing a new electric circuit to be formed, with part of the current being diverted through the armature and the firing device which are planted in the track bed.

A powerful electromagnetic field then swiftly begins to build around the armature, and very soon the EM field is strong enough to trigger the firing mechanism, which forces the projectile upwards out of the launcher at a very high velocity. The projectile bursts through the carriage floor, and then, a fraction of a second later the delayed-action fuse detonates the bomb inside the carriage.

Part 4: why there were multiple holes or craters in the floors of the carriages, and also why many passengers felt severe electric shocks. In addition, explain why the explosions were not exactly synchronous, and also why the perps. chose those particular sites to plant the devices.

There is compelling evidence from the 7/7 Inquest that some of the carriages had more than one hole punched through their floors. This probably means that the perps. planted more than one firing device at each site, so that if one, or even two misfired, then at least one projectile would “successfully” explode inside the carriages. So they simply brought six coupler-units, three firing devices with armatures, and three projectiles with them each time. They laid these just a few metres apart, once again hidden in the track between the sleepers. Extra cable was used to connected these armatures to the coupler-units attached to the electric current rails, plus additional lengths of flex to the battery and sensor. The power from the DC current would just as readily launch three projectiles as a single one. The detonations would even occur simultaneously so that passengers would only hear one explosion.

The evidence produced at the 7/7 Inquest does suggest that that there was only one large hole in the floor of the carriage at Aldgate. But it would appear that at Russell Square there were two holes in the train – plus one device that misfired. This projectile probably zoomed off at a tangent, ricocheted, and did major damage to the concrete lining of the tunnel floor. (Passengers in this Piccadilly Line carriage recall bright yellow/orange flashes lighting up the tunnel outside the train.) Only at Edgware Road were there three large holes in the floor, and here the combined effect of these explosions was obviously powerful enough to lift the carriage off the rails (certainly they were great enough to force upwards the utility hatches in all three tube trains.)

It is interesting to note that the former head of the CIA’s anti-terror unit – Vincent Cannistaro – told the Guardian newspaper soon after the 7/7 event, that “two unexploded bombs were recovered, as well as some mechanical timing devices.”

Many passengers on all three trains felt they were being subjected to electric shocks even before the explosions. Why should this be ? We probably need an expert on the properties of electricity and electromagnetism to explain this phenomenon, but could it be that as the EM field builds up around the armature of the firing device, a strong magnetic field is also being created between the two current rails as well ?

If this be so, then the nearside running rail falls inside this magnetic field, and thus some of the electric current may be inducted into this rail, and then through the wheels of the passing train into the carriages above. The passengers certainly felt severe electric shocks, but it is interesting than none were actually electrocuted. This suggests that it was indeed Direct Current (DC) that they were experiencing and not Alternating Current (AC). The latter has a high voltage which of course can be fatal, while DC has a high current but low voltage.

Another curious fact that many passengers also recorded, was that they not only received electric shocks before the explosions, but also AFTER they had taken place. Now the reason for this could be that once the projectile had left the launcher and done its deadly work, there would still be electricity passing between the live rail, the armature and the negative rail. The circuit would still be intact!. This means that electricity continues to be inducted into the train carriage via the nearside running rail. The power would only cut out when the circuit breaker at the nearby feeder station registered a serious fault in the system.

The large scale power failures that affected other sections of the tube network that morning could well be due to the damage done to the AC supply cables. These run alongside the tunnels beside the trains, and could very easily have been struck and severed by debris thrown out by the explosions.

The perpetrators of 7/7 were probably hoping that the explosions would occur simultaneously, but knew in practise that this was not very likely because they could not guarantee that the three tube trains would be passing over the respective sensors exactly at the same moment. The frequency of trains in the rush hour meant that the best they could realistically hope for would be for the detonations to occur within two or three minutes of each other. (The 7/7 Inquest stated that the explosions actually occurred over a time span of 52 seconds within the same minute of 8.49am – but this may, or may not be true, because the Piccadilly Line was experiencing severe delays that morning because of an earlier fire at Caledonian Road tube station.)

Research suggests that electrical feeder stations do exist very near to the sites where the explosions took place. By typing in “London Underground Power Supply” on Google, and then paging-up “Track and Traction Current”, before scrolling down to “Traction Current Sections”, we will find listed under the different tube lines, that a feeder station exists at Aldgate, which supplies power to the Circle Line between Aldgate and Moorgate; and also one at Baker Street (one stop before Edgware Road) which serves the section of line between there and Bouverie Place, Paddington. There is also a feeder station at Russell Square on the Piccadilly Line, which feeds power into the section of track between there and Holloway Road.

Perhaps this is not a coincidence – the three sites were deliberately chosen in close proximity to these feeder stations in order to maximise the power of the electric current. This is because DC current is not very efficient over long distances.