I believe they are making a big mistake in trying to find the locomotive with metal detectors. That is the wrong tool for the job. The correct tool is a magnetometer. And even that instrument is only half the tool. The other half is the proper technique and interpretation of the result.

The article does say that the searchers will use a special metal detector that has a detection range of 20 feet. I have no idea what metal detector that would be, but I am highly skeptical. Metal detectors definitely work to find lost objects, but as a general observation, I believe there is an unusually large amount of smoke and mirrors surrounding the category of metal detectors and the claims of their capabilities.

But for finding a buried locomotive, using a magnetometer is like shooting fish in a barrel, as they say. Metal detectors create their own magnetic field that must envelop the object of search, and they read that field to find the effect of the object. However, the earth creates its own magnetic field that also envelops the object of search. Magnetometers read that earth field to find the effect of the object.

When you move a metal detector, its self-created electromagnetic field moves with it. When using a magnetometer, the earth magnetic field remains fixed, and you move the magnetometer around within that fixed field. With a metal detector, the electromagnetic field is about the size of the coil. With a magnetometer, the earth magnetic field is practically unlimited in size. So a large object like a locomotive causes a large anomaly in the magnetic field. By taking readings with a magnetometer within that anomaly, you essentially map the anomaly, or magnetic signature.

At best, with a metal detector, you are going to get readings from all the nearby junk such as spikes, track parts, and other metallic trash items. You will never find the big picture represented by the electromagnetic signature of the locomotive. But a magnetometer will find that big picture.

Magnetometers are rather expensive, but sometimes they can be rented. One day’s work with a magnetometer would find the locomotive if it is there. The worst outcome would be if the magnetometer finds an anomaly that is so complex that it is inconclusive. But here is one thing for certain: If the magnetometer does not find an anomaly, there is no locomotive there.

You need to borrow a P-3 Orion... or a scale model with working MAD.

This turned up on my Facebook page, courtesy of Anthony R. De Seta, a photographer who's been spending a bit of time on the Northern Central/Steam Into History line.

https://scontent-b-ord.xx.fbcdn.net/hph ... 1625_n.jpg

I would have to look in my collection of magazines downstairs to get the exact issue, but it's from Railroad magazine, and I believe it dates to the 1940s.

Happy Holidays!

Hey! I recognize that picture, I think! It's by Pennoyer -- and the story behind it is in his book. I will have to look and see if I have the description (including a story about the trees, and the color of the cars. IIRC).