Electrical connector between engine and tender on steam loco

[amadlinger]

Hi all,

I'm curious what types of electrical connectors folks are using between the engine and tender on their steam locomotives, for power to the headlight, cab lights, etc. Note that I am referring to low current connectors to power accessory lights on steam engines, not high current connectors for battery powered locomotives.

I have mainly seen many people use either RCA connectors or Cinch Jones connectors, which are nice because they are compact and readily available. But I have found they are succeptible both to vibrating loose and to contact corrosion, and would prefer a connector that makes a good, solid connection such as an Amphenol "military" connector...but that seems like overkill.

Thoughts? Suggestions?

Sincerely,
Adam

[ccvstmr]

Adam...

Have been using 2-pole trailer connectors for almost 20 years between loco and tender and between tender and stock car with power module. Relatively inexpensive. Readily available. Soldering iron and shrink tubing and you're good to go if replacement is needed. Need more circuits, believe these come in 3 and 4 pole connector configurations.

Carl B.

[hoppercar]

Gosh, I sure miss radio shack......they used to have all that neat stuff

[JBodenmann]

Hello My Friends
I have used these.
https://www.allelectronics.com/item/con ... air/1.html
Jack

[Greg_Lewis]

I wanted something that looked railroady, so I took a panel mount DC connector like the one in the first photo below and stuck the threaded part into a copper 45 degree tube fitting. Then I took the plug section out of its housing and made up a housing with a hex on it which was threaded to screw onto the panel mount thread. I don't remember the thread but I did have to buy a tap for that. Thus the connection screws together and won’t come apart, and looks good.


Here are the parts I started with:

The panel mount half is stuck into a copper tube fitting. At the back end you can see the mounting block that screws under the end beam of whatever rolling stock it needs to attach to.

The plug end of the connector.

The plug end at home in its shop-made housing.

The complete assembly. All that's missing is the wire from the plug end that would come out of the housing on the right.

[kcameron]

I would also suggest consideration of the Anderson Power Poll connector. Used by many ham radio folk for field power. The indoor folk use it for Free-mo layouts. Built for plenty of cycles good contact construction and you can pack them into whatever number of pins you need.
https://powerwerx.com/anderson-power-po ... connectors
Granted they come in all sorts of current ratings and for lights, it is a bit of overkill. But convenient and easy to replace parts as needed.

[Dick_Morris]

Just curious, with as little power that LEDs consume is it still necessary to have a battery so large that it can't be hidden on the locomotive?

[davidk]

Hi Adam,
I went through the same process a while ago. Agreed that Amphenol mil-spec connectors seem overkill.
What I found and ended up using was the Souriau UTS series of connectors. These are a plastic-body version of a mil-spec connector and are available from 2 to 32 contacts. Much cheaper than the metal-bodied mil-spec connectors. For example, I used a 4-way plug and socket, part numbers UTS6JC8E4P and UTS78E4S.
Obviously, being plastic-bodied, extremes of temperature must be avoided. The UTS connectors have a max temperature rating of 221degF.
I bought mine from RS Components in the UK, but would imagine there are plenty of distributors in the US.
Hope this helps
David

[amadlinger]

Hi all,

Thank you for the execllent information and persepectives, this gives me the idea I was looking for. Many thanks again!

Sincerely,
Adam

[amadlinger]

Hi all,

With regard to Dick's comment about on-board batteries, I would add that the rechargeable LiPo (lithium polymer) batteries that are on the market these days pack a tremendous amount of punch in a very compact footprint. I have never used them myself, but based on the specs and what RC folks are saying it would seem that they would probably be adequate to even power incandescent light bulbs without much issue. Of course, there are some impressive videos out there showing what happens when the LiPo batteries fail, so that's definitely a consideration as well.

I personally am still running the incandescent bulbs for their perfect golden glow; I have tried the "warm white" LEDs but they just aren't quite there...yet.

Sincerely,
Adam

[Crosshead4]

I’m using an SAE connector right now. Only need two wires for the supply as all my switches are on the cab. It’s nice as it makes it impossible to get the polarity wrong when plugging the charger in.

[ChuckHackett-844]

In my mind it depends on how many connections you need. When I rebuilt the Northern I replaced the Cinch-Jones with a common DB-25. They are very common and easily obtained. There is also a smaller DB-9 version. I mounted the female in a block on the back of the loco and the tender has a short cable with the male. Has worked great for years. Seems to hold up to dirt/oil well.

The only issue is that I used the hold-down screws to hold them together which is a bit fiddly to deal with (but I don't separate the loco/tender that much). If I were to do it again I would go with the same connector but a sliding type hold-down or a simple clamp/elastic over the male shell.