Mallard R3173 or R3371?

[Bobby B]

Hi

I'm looking at a R3173 Mallard (5 pole loco drive DCC reddy). Is the R3371 the same, other than the tender is linked (tethered) to the loco?

[atom3624]

I'm sure Going Spare will clarify this issue.

Personally, I'd find an excellent, probably used R2339.

Al.

[Topcat2018]

I'm not familiar with all the models and variations of Chinese-made loco drive A4s but I think there are probably three basic configurations.

1. The earlier ones have a connector on the drawbar which has finger contacts above and a fork contact below. Depending on the model number these may or may not be DCC ready. The motor or power to the DCC decoder in the loco is connected to the tender as well as to the main wheels of the loco. As there is only a 2 pin connection to the tender presumably a TTS sound decoder can't be fitted in the tender.
2. Locos such as R3280 4496 Golden Shuttle are DCC ready and have a permanent metal linkage between the loco and the tender but no electrical connection to the tender, so presumably a TTS sound decoder can't be fitted in the tender.
3. Locos such as R3285TTS 4469 Gadwall have a permanent metal linkage between the loco and the tender and also a 4 pin connector between the loco and the tender. They are DCC fitted and have a TTS sound decoder in the tender. I don't know if there is a R3285 or other locos that have similar connections but don't have the DCC decoder or sound decoder fitted, but I guess there are.

[Going Spare]

Both are Railroad-series models with reduced detailing but R3173 was the 75th Anniversary limited edition with, from images on the net, shaded letters and numerals. Both appear to be carrying the DCC socket on the loco chassis and, although there are no Service Sheets specifically covering either loco, as it has a sprung electrical drawbar, I would expect R3173 to have a dummy ringfield motor block with pick-ups on two of the tender wheelsets whereas R3371 with a plain bar drawbar, pick up is through only the loco driving wheels.

[atom3624]

Sorry GS for 'volunteering' you, but you always confirm these kinds of requests!!

Al.

[ColinB]

I am sure I have seen a thread about this earlier. Sam's trains did a review of R3371 and I think it was pretty complimentary. The mechanism on both is the same although I suspect R3371 might well have a heavier chassis, I am not sure when Hornby changed their A3/A4 Railroad chassis, but I suspect R3173 may have the earlier one which has a plastic pony truck as opposed to the diecast one. I think Sam highlighted that R3371 has no tender pickups whereas from GS's post it looks like R3171 does. R3371 will have a three motor with flywheel whereas I suspect R3173 has a five pole motor with no flywheel, but it all depends when Hornby went to the newer chassis as to that fact.

[Going Spare]

Al - I do not mind in the slightest being 'volunteered'; indeed, I thank you for the vote of confidence! Any comments offered are no longer borne out of any inside knowledge, rather simply memory (sometimes not so good!) and an interpretation of information in the public domain, and are therefore open to alternative views - see below

Colin - further investigation shows the 3-pole motor with flywheel, pony truck frame cast as part of the main chassis block and a simple bar drawbar were introduced on the Railroad Flying Scotsman with R3086 in 2012 so it would seem logical to infer that the same set-up would apply to 2013 release A4 R3173 but that loco's retention of the sprung drawbar shows there are pitfalls in applying logic! Thus you are correct in drawing attention to the probability of different motors as well, which I had missed.

[Fishmanoz]

Topcat, in your No 2, you can always add the 4-pin plug and socket to put a TTS in the tender.

[Topcat2018]

@Fishmanoz. Thanks for that tip, I didn't know that. I've not actually separated the Golden Shuttle loco from its tender as I am not using DCC or TTS at present.

[96RAF]

@topcat

In your 1 above you can strip the electrical bits off that unreliable live drawbar and install a standard 4-pin plug and socket in lieu.

This allows the decoder to stay in the loco and the speaker wires to be extended and routed to the tender through the plug and socket, where the speaker is mounted.

Wiring is arranged with the speaker wires using inside two pins and tender pickups using outer two pins.

The tender post simply drops onto the drawbar as before.

[Going Spare]

@Topcat

If you envisage adopting sound in the foreseeable future, converting some of your loco tenders as suggested above might be made a little easier if you source sound-ready chassis frames which have provision to take the 4-pin connector socket and the DCC 8-pin socket, are moulded with a capture for the Hornby round speaker, have pick-ups and have compatible fixings for your tender bodies.

A browse through the Service Sheets which show loco and tender chassis in exploded form might be worth the time: go to Product Support in the Support menu on the home page.

ColinB has completed a number of these upgrade conversions and I am sure will have answers to any questions you may have. [Another volunteering!].

[Bobby B]

Fabulous results from you all