Double heading trains on DC – the ‘dummy loco’ debate

[Newportnobby]

AFAIK, DCC users can 'speed match' locos using their gizmos so this really applies to DC users

Speed matching for me is putting two locos on an oval of track and seeing whether one catches up with the other. Even if they're close, it's still not something I tend to do. Just take a motor out of one of them, I hear you say. Simples.
I've never had the body off a loco in all my 45+ years in N gauge.

Having said that, an exception seems to be Farish's Blue Pullman which is awesome.

Now Dapol, bless em, did produce a dummy Hymek and a dummy class 121 (both of which I have) so I could play out a scenario of a steamer rescuing a broken down diseasel (or vice versa in very extreme circumstances, you understand )

Let's face it, there have been some shockingly unreliable diesels manufactured in the past – witness class 17s and 28s to mention but two (real ones, I mean, not the models).

Many moons ago, when Dave Jones was bringing out his class 17 he was actually going to sell them as twin packs, one powered, one not and I had my name down for that, especially having seen them in the flesh at the Stafford Show when DJ Models attended. That pack never came to fruition when EFE launched the class 17.

We are told the price differential between a powered model and unpowered model just makes it not worth doing as the motors are cheap as chips and it's easier to manage stocks when there's only one version. That basically says to a DC user if you buy two powered units and they don't match – tough (or remove the motor from one)

I would have loved a twin pack of the class 17 and the class 28,  and I dare say if ever a class 21 was released so would purchasers of that particular class. Our models are all hand built so, potentially, every one varies from another in some respect. The chances of getting two that run close enough to double head are not high.

I'd be interested to hear other views

[martyn]

Maybe not quite what you're looking for, Mick.

I swapped Poole motors for Tramfabriek in my pair of Poole cl 20s, and they run fine together. Much more control, no speeding up and slowing down on gradients.

I also run a split chassis 25 with a de-motored Poole one.

I have also a pair of 24s which are pretty close and sometimes double head.

And I did have a pair of Ivatt 2mt moguls which ran well together (one is now under an LNER L1).

All on dc.

Martyn

[Newportnobby]

Thanks, Martyn. I reckon I could run a couple of class 24s as well , but other than that you've either remotored or removed a motor. I'm not capable of either.
It's still a case of, if DC, do it the hard way

[ntpntpntp]

Generally I'd say to create a dummy loco remove more than just the motor:  also pickups and as much of the gearing as you can to minimise drag, plus any removable weights.

If your pair of locos are reasonably well matched for speed across the range then it's fine to double-head.  Mismatched locos will of course cause bucking and dragging which is no good for the mechanisms nor coupling reliability.

Totally surprised. you say you've never had the body off a loco!  I've been dismantling and servicing my own locos since my Triang OO days when I was about 10 in the early 1970s.   Nothing to be scared of

[Newportnobby]

Totally surprised. you say you've never had the body off a loco!  I've been dismantling and servicing my own locos since my Triang OO days when I was about 10 in the early 1970s.  Nothing to be scared of

There is when you're a cack handed idiot with 'shaky hand syndrome'!!

As a continental modeller, do the manufacturers offer 'dummy' locos?

[EtchedPixels]

For some locos (eg the old Farish 20/37/47 I think it is) there are resin replacement chassis kits originally done by BR Lines so you can just pick up a bodyshell, paint it for one end of something like the South Wales top/tail sets and avoid having to buy an old loco.

I've stripped the motors out of a few trashed models because busted ones are/were cheap on ebay. The plastic chassis ones like some of the Dapols are really easy to work with as you can just chop them about. The metal chassis ones often need more violence and it can be easier to just keep the bogies and build a new chassis out of plasticard then glue the battery box on.

I try and keep the pickups because then you can fit sound and keep lights and stuff working. I've got an old Farish class 20 pair that's one sound, one motorised and a GBRF 73 pair done the same way but by adding back bits Dapol removed from the dummy version. Also a dummy hymek with sound and there's space to use cheaper OO gauge aimed sound chips.

For both motorised providing they are similar-ish speeds it seems to work but DCC or DC you have the problem of one end stalling on dirt on a long train and the whole lot derailing.

[EtchedPixels]

As a continental modeller, do the manufacturers offer 'dummy' locos?

European ones not so much in my experience except for things like railcar sets or units with two power cars one motorised (so like most of our HST models). There are some though.

Japanese though there are lots of unmotorised sets both as add ons to powered sets, and also stuff that is sold only as unmotorised collector stuff but which has optional motorising kits.

[ntpntpntp]

As a continental modeller, do the manufacturers offer 'dummy' locos?

There have been a handful over the years. Minitrix BR 155 electric locos come to mind. That had a solid drawbar between the two locos (hence the missing coupling in Hatton's photo)



I think Minitrix or Brawa did a twin pack of "Ludmilla" diesels. [edit] Minitrix


One of Fleischmann's earliest N gauge sound locos - a permanently coupled pair of BR 218 diesels, with the sound decoder and speaker in the dummy loco.  I have one of these, originally the UK Fleischmann importer's demo model which he gave to me when I bought a DCC starter set   It had had its main drive gears removed and sat on a static length of track. Simple to restore to full working order. Must be at least 20 years old now.
 

[Bob G]

Didn't Dapol/Kernow get a roasting for their recent class 50 GBRF pair, when one 50 was unpowered?
Maybe it was the £250 (DC) - £300 (DCC fitted) original price point that was to blame?

Bob G

[port perran]

I regularly double head my locomotives and have done for years with no problem.

There are exceptions of course where a power/speed mismatch is obvious eg a Castle with a Dapol small prairie  or pannier or when one of the locomotives is much lighter than the other eg Dapol M7.

I also have no problems when running modern image with, for example, a pair of 66s either double heading or top and tailing.
I also often run special trains with a King or Castle at the head and a 66 bringing up the rear.

Or am I missing the point?
Are we only talking about genuine dummy locomotives?

[ntpntpntp]

For some locos (eg the old Farish 20/37/47 I think it is) there are resin replacement chassis kits originally done by BR Lines ...

There was a guy producing 3D printed dummy chassis for various locos.  I didn't pay much attention to who it was as British N not my area of interest.

[zwilnik]

An overcomplicated solution, but it would be nice to have a 'clutch' of some sort on locos that can be double headed. To effectively disconnect the drive train and let them freewheel.

That would make it so they can be used powered or unpowered. Downside is a big chunk of mechanical overcomplicating for their 99% use case.

[tunneroner61]

It's Bees Hill www.beeshillmodels.co.uk who does the dummy chassis for a few diesels. I have used them for a 20 and a 25 with no problems.