Monday, February 17, 2014

Physical Security – Another Perspective

There is an interesting piece on detailing complaints from Sen, Schumer (D,NY) about the ability of power companies to veto security requirements. I’ll leave the discussion of the politics of electrical system security to the folks that deal with it on a routine basis. I would like to point out a serious flaw in Shumer’s reasoning, a flaw that has been bandied about quite a bit in discussions of this attack on Silicon Valley transformer stations; the assumption that these stations can be protected against a serious physical attack.

The Target

You see these stations scattered all around the country. Some of them are bigger and some are smaller, but they all have a couple of things in common. First off, the purpose of these stations is to transform the very-high voltage cross country transmission lines into the lower voltage used by local transmission networks. The equipment is widely spaced to ensure that there is room to work without worrying about sparks jumping from one set of equipment to another. The big boxes hold huge coils of copper wire surrounded by a cooling fluid, typically an oil of some sort.

If you put a hole in the outer jacket the oil drains out, the transformer overheats and at the very least shuts down. If a shooter is extremely lucky or knowledgeable the bullet will strike and damage the copper coil and cause an immediate shut down.

Another vulnerable area in these stations are the insulators that protect the physical structure of the towers and such from the high voltage transiting the lines. If these are damaged to the point that they allow arcing to the towers or fail to continue to support the transmission lines, you have another immediate shutdown of power transmission.

The slower the shut down the easier it is for the transmission company to re-route the power through other parts of the station or to other stations in a systems with a certain amount of redundancy. The more parts of the system that are taken off-line the more difficult it is to keep the power flowing. It is a testament to the system operator that the loss of 17 transformers at a single transmission station did not take down a large portion of California’s power grid.


It seems as if this attack was executed by multiple shooters putting holes in transformer shells. This does not take snipers unless they are working from really long distances away from the site. Any trained infantryman (or hunter for that matter) can consistently hit a man-sized silhouette at about 300 meters over open sites. A transformer is a much larger target. Put a scope on the rifle and a relatively experienced shooter with a reasonable hunting rifle could engage those targets all day long out to a range of 1000 meters. A trained sniper could nearly double that distance depending on the weapon.

How hard would it be to find a firing position within 1000 meters of a transformer station? Not hard at all at any station that I have seen. Finding a concealed location would be a bit more difficult in most cases, but there really isn’t a need for concealment. These stations are typically unmanned and certainly don’t have an on-site security force to dissuade people from shooting at the facility.

There has been talk of installing a variety of ballistic barriers to protect the transformers at these sites (I suggested Kevlar® curtains on a LinkedIn page a couple of weeks ago) and these would certainly make it harder to take out a transformer (certainly a high-value target in the terms of cost and time-to-replace), but that just would not work to protect the high-voltage insulators. These are harder targets to hit, but bullets are cheap and just a little marksmanship training with a good scoped-hunting rifle would make them easy targets at reasonable ranges.

Even if you were able to harden those insulators and install blast shields, it would not take much more effort to cut a fence and place improvised explosive devices on the transformers. The only way to stop that would be to place a sizeable security team on site and put a real barrier plan into place. Even then, an experienced and determined assault team could get through. Just ask any Iraq or Afghanistan vet how hard it would be to penetrate these facilities. And remember, determined foes managed to execute routine attacks in the Green Zone in Bagdad, one of the most heavily guarded areas in the world.

Security Measures

Some sort of security measures are going to have to be put into place, but they will have to be minimal or the systems will become too costly to operate and the terrorist’s objectives will have been achieved without firing a shot. But it is not going to be possible to put in enough security to stop a determined adversary from shutting down multiple transformer stations. Perfect Security Is NOT Possible.

No the best way to deal with this potential problem is to make these areas non-targets. Make the systems so redundant that taking out one, two or even three of these stations will not be a catastrophic event. Actually, the attack outside of San Jose was one of the best security measures that we could have asked for; the utility was able to continue to supply electricity to its customers even after a significantly successful attack. This means, that as long as the Schumer’s of the world don’t over-react (which is what they do by training and inclination), most terrorist groups will have crossed these off of their target list as there are much easier targets to successfully engage.

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