One of these just turned up in my "backyard":

https://americanhistory.si.edu/collecti ... mah_847437

He's asking $200, which includes case, six various scale rulers, accessories, instruction cards, and even the tiny oil bottle. The Smithsonian's is from 1878; the seller is claiming his is 1889 (probable patent date). He claims other examples have sold for $400-500.

If there is anyone who wants/needs this for actual operation/restoration work on a steam locomotive or railroad, I am willing to follow up on this on their behalf (meaning: You know enough to tell me what to look for in the case, etc.). PM me backchannel.

I've never heard of anyone using an indicator to check the valves of a locomotive, either in preservation or in historic practice. That doesn't mean it couldn't be done, and I'd be interested in knowing if it was. The only references I've seen to use of these on locomotives was in trials of new engine classes, in conjunction with dynamometer cars, when sheds were erected on the pilot to house the operator of the indicator.

Many years ago we got to see a curator take indicator cards of one of the engines in Henry Ford's "Edison power house" reconstruction at Greenfield Village, just for grins. It was fascinating to see the revolving drum and moving pen in time with the crosshead. That display is no longer steamed.

Indicators turn up fairly often in antique stores. They were the timing light of the factory-engine era. But now timing lights are obsolete.

Aarne Frobom
Lap City, Michigan

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Aarne,
Please forgive the splitting of hairs but I would offer that dividers and a ruler were the timing light of the era and an indicator would be the Sunn Machine of the era.

I would agree with Kelly that while much less elegant the electronic approach would likely be more practical............mld

But they can be excellent diagnostic tools, if you are trying to track down odd blows or pounds that just eyes and ears can't locate.

Chris Dewitt from the Nevada State Railroad Museum in Carson City has and has used one, I believe on Leviathan. Historic photos of the process show chairs suspended along the side of the locomotive for the tester to sit on...

Bruce Babcock and Leviathon. The indicator is barely seen. He rode on this platform and took cards.

I am preparing to take indicator cards on the J&L 58, the main reason being to help me determine the source of the offbeat exhaust and also as a training tool. I have a Crosby indicator, reducing motion and started work on brackets for a seat while I ride up front to take the cards. I had to drill and tap indicator ports in the cylinders as well.

There are many photos of doghouses built on the pilots of locomotives for the purpose of taking indicator cards and otherwise monitoring the performance of a locomotive. It was done from time to time but not often due to the difficulty and inherent danger involved.

We intend to hold annual steam schools here at the J&LNG and I would like to add the taking of indicator cards as part of the curriculum. Steam schools tend to focus heavily on boiler operation but I would like to add some stuff on how the engine itself operates. Besides, it is one of those "lost arts" that should survive into the 21st. century and beyond.

Another fascinating tool to go along with these is a planimeter. It is essentially a mechanical integration calculator. You trace around the indicator curve and the planimeter scale racks up the total enclosed area. The area inside the indicator curve, with appropriate scale and units conversion factors, represents the total work that the cylinder did in one cycle.

There's a great discussion on indicators on locomotives here, https://www.practicalmachinist.com/vb/a ... os-260781/. As a kid I recall screaming questions into the ears of to Harold Crouch who was on that ride and wrote the article. There's some neat photos of Harold and his team taking indicator cards sitting in a little box built in front of the cylinders of a large Niagara! Imagine what that ride must of been like at speed!

I an only on my phone here but maybe someone can repost some of those photos or the link to the original article here. To me talking indicator cards at speed on the side of a locomotive always sounded like one of the most awesome/fascinating things ever.

Adam, its been a long time! How have you been? I dropped out of participating in Practical Machinist a few years ago, just too many things to do, but maybe I need to start participating again. Lots of good useful knowledge over there.

We have a straight stretch of track on the J&LNG that is uphill, so it would be possible to take indicator cards with the locomotive under load without needing to move at a high speed. I'm working out the design of the testing rig to include a tractor seat and grab irons so there is somewhere for me to ride. I have been making youtube videos of our project for a few years now and I think I will do one on taking cards, so that everyone can tell me that I am doing it wrong!