Combinations on excursion trains.

[railfan365]

I've seen videos of excursion trains led by a steam locomotive followed by 2 tenders and a diesel locomotive. My two questions are: 1. How does the fireman get to the fuel and water in that second tender?, and 2. Is the diesel locomtoive actually providing power, or is it there in resrve? Thanks.

[Allen Hazen]

I suspect there is a lot of variety in the details, but...
(1) It is certainly possible to link anelectronic control box to a steam locomotive's throttle so as to allow the engineer to control a following diesel through its m.u. cables: the diesel "thinks" it is getting commands from a leading diesel unit. The Clinchfield did this in the 1960s (I think-- certainly by the 1970s) so their anciet preserved steamer could lead holiday specials with one or two diesel units doing most of the hard work.
(2) A steam locomotive uses a lot more water than coal. My guess is that an excursion steamer with two tenders has fuel only in the first one: the second tender is a "canteen" (I think the N&W, which used them in regular service in the 1950s, called them that) carrying only water.

[wurlitzer153]

1. How does the fireman get to the fuel and water in that second tender?

The second tender just carries water. A simple hose connects the two and gravity does the rest. On an oil burning locomotive, it might be possible to store extra fuel in a similar manner to the cab-forwards, but I doubt it has been done on any large scale.

2. Is the diesel locomtoive actually providing power, or is it there in resrve? Thanks.

Several of the large mainline engines (844, 765, 4449, etc.) have M.U. control boxes with cables running through the tenders. Other operations use radio to tell a second crew in the diesel how hard to pull. How much the diesel is used depends on the engineer, length of train, etc. On 765's long ferry moves last year, the diesel was used to conserve fuel.

Sometimes the diesel is there for other reasons. Amtrak sponsored excursions require a diesel to provide electricity for the train's AC and lights. 765 last year needed the diesel to power the cab signals. Finally, it helps with dynamic breaking.

[railfan365]

Thanks for the replies. The extra tender(s) and diesel power looked strange to me, but did think to wonder about a purpose for them.

[Engineer Spike]

I'm surprised the cab signals weren't run on the steamer's electrical system. Lots of them had it in service. B&M 3713 at Steamtown did. Didn't they install cs on C&O 614 for the runs on New Jersey Transit?

The control boxes for diesels on steamers is the same as a cab car in push-pull passenger trains.