JeffG wrote:NX Panel layout drawing? Nope, it's somehow a security risk!
As my day job is in the records policy area, albeit in Australia, I thought I'd comment on this.
Sadly, we live in a world where there are real threats to people. And the area of our interest, signalling, is largely about keeping people safe. Signalling systems are consequently a legitimate security concern. My feeling is that it will become harder, not easier, to study modern signalling systems as time passes. This is one reason why the focus of my interest is shifting to historical signalling.
FOI officers are clerks, not subject matter experts. They have training in FOI law, have a manual, know the precedents, and can crank the handle of the FOI process. They have no idea about what a signalling drawing even shows. Signalling engineers do understand what the drawing shows, but are not experts in FOI. Neither the FOI clerks or the signalling engineers are experts in security. They do not have the training or experience to judge how a drawing could be used to mount an attack. But the FOI clerk and signalling engineer will be held accountable if a drawing is released and it is used to mount an attack. This leads to conservative decision making.
On a less generous note. As you observe, the FOI process is expensive. It takes time (read pounds) to merely find the relevant information, let alone decide whether it is innocuous or note. Then it takes more time (more pounds) to redact the information. Redaction can range from removing genuinely sensitive information to removing the initials of the staff who prepared the drawing (for privacy reasons). Finally, a copy needs to be produced and sent to you. It's much easier and cheaper to simply deny access. It's even easier (cheaper) if a decision has already been made about a particular class of drawings.
If you see that a class of information has already been refused, there is no point in asking for an example of that class - unless you are prepared to go through the appeal process. On the other hand, if an example has already been released, this is also a precedent. This is the value of sites like whatdotheyknow.
If you really think that a particular type of drawing has been wrongly withheld, there is always the appeals process. Be aware though, that none of the parties involved (FOI officers, signal engineers, appeals board, or you) have any real basis for understanding the risk of a drawing. Again, this is likely to result in a conservative outcome.
As for the particular type of drawing mentioned, panel layouts, I'd suspect that the main concern would be the level crossing CCTV screens. FOI officers have manuals giving the types of information not to be released, and information about CCTV systems is invariably on the list. CCTV is a button pusher, as it is almost always used for security surveillance. This is why you can take pictures at stations, but not of CCTV equipment at stations. The fact that level crossing CCTV screens are not used for surveillance is largely irrelevant - see my earlier comments about knowledge and cost. Arguing against the manual is an uphill battle.
My suggestion would be to ask for drawings of installations that no longer exist. Ideally, the whole line would be closed and removed. Make sure you emphasise this point in the FOI request. Your request may still be rejected due to 1) the manual makes no distinction between in-service and out-of-service installations, 2) the drawings no longer exist/are too hard to find, 3) knowledge of one installation (even removed) will give you information about in-service installations, or 4) no-one will have any knowledge to judge your claim that the installation no longer exists.