Does OO = HO??

Discussion in 'FAQs' started by Cannonball, Dec 20, 2006.

  1. Cannonball

    Cannonball More Trains Than Brains

    I'm looking at a Flying Scotsman set on eBay. The set is listed as OO. Is this the same as HO or a different gauge altogether? I'd really like to find an HO Flying Scotsman but they seem hard to come by here in the States.
  2. Russ Bellinis

    Russ Bellinis Active Member

    Ho is scaled at 3.5mm to a foot. I think oo is scaled at 4mm per foot, but runs on the same track as ho.
  3. Cannonball

    Cannonball More Trains Than Brains

    I'm guessing it would take a wider curve radius though?
  4. MasonJar

    MasonJar It's not rocket surgery

    But OO engines run on HO track, so youd' be safe with it. It will technically be a bit oversized, since OO I believe is 1:76 and HO is 1:87.

  5. 60103

    60103 Pooh Bah

    Cannonball: since you said "set", I'm going to assume it's one by Hornby, who make a Flying Scotsman in OO.
    The track gauge is 16.5mm, which is HO. The body is scaled to 4mm=1' which is OO. The loco may run through North American turnouts and such, but the wheel standards are not NMRA, and nowhere near RP25.
    The track in the set is probably 18" radius or a bit less. The loco may run on curves as small as 13.5, but I think the newer ones have been tightened up a bit. Probably won't like O27. Hornby have made 3 main series of models; the first ones ran on tight curves.
    The scale may be bigger, but the prototype is smaller, so the train is about the same mass as HO.
    AFAIK, there are no HO Flying Scotsmen. HO scale British stuff is extremely scarce. There are occasional movements for HO, but it would mean producing all the accessories from scratch. Rivarossi made an exquisite Royal Scot in HO, and nobody bought it.
    The track and wheels are not compatible with Lionel's pre-war OO, which was the accurate gauge.
  6. Cannonball

    Cannonball More Trains Than Brains

    Yeah, it's a Hornby set. And I'm not looking to put it on O27 track. I just want to know if it will run on my daughter's HO set. I think her's is an 18" radius (Or 21"... Can't remember for sure and it's wrapped up for X-mas.) so I think you've answered my question to the affirmative? :confused: ;)
  7. RobertInOntario

    RobertInOntario Active Member

    I mainly model a British layout in 00 but occasionally run my HO North American trains. 00 and H0 are totally compatible -- I do it a lot. HO is an accurate scale whereas 00 is a fudged scale. Since real life British locos are generally smaller than N. American ones, model manufacturers originally had to make the British bodies oversized to accommodate the motors. The result is that British 00 locos look fine and accurate from the side but, when viewed head-on, you can tell that their wheel gauge is too narrow. (Please feel to correct me, anyone, if I've made any errors here.)

    Being a visual person, the way I view it is that 00 is a tiny fraction closer to 0 scale whereas HO is a tiny bit closer to N scale! There are a few British scales out now that are scale-accurate, such as P4. I believe P4 uses a wider gauge track than HO's 16.5mm. Most British modelers are content to tolerate the inaccuracies of 00 but a few prefer to be much more accurate and go for P4.

    At any rate, you should have no trouble at all running 00 stock on HO track and vice versa!

  8. 60103

    60103 Pooh Bah

    I think there was another consideration than the motors. way back when, model wheels were a lot wider than they are now. British locos have a lot of places where frames, splashers, bits of footplate, went along outside the wheels. Wheels at scale gauge would have forced these items to be a scale foot or two wider than proper, giving a diffeent wierd look and a narrow gauge appearance. As wheels have thinned down, gauges widened out to scale.
  9. nkp174

    nkp174 Active Member

    I believe the British had a head start in model railroading...such would cause a greater concern over motors and less concern over track gauge. While you could probably fit (3) B12 ten wheelers in a 2-8-8-2, early american HO models were 0-4-0s, 4-4-0s, 4-6-0s, 0-6-0s, and other engines that would have had the same motor issues as British motive power.
  10. Mike14xx

    Mike14xx New Member

    I should know this, most of my collection is hornby. You can run them on the same track but I do not advise using the same controller. I have a bachmann Acela train set and when I used one of my hornby trains with its controller and went to use it with Acela it almost broke it. Acela was going top speed even though the speed control knob was at zero. So there is my very useful 2 cents.
  11. Cannonball

    Cannonball More Trains Than Brains

    Any ideas what caused this?
  12. Collyn

    Collyn Member

    different voltage and amps. the hornby is meant for a 220v controller at half the amperage.
  13. Cannonball

    Cannonball More Trains Than Brains

    Well, poo.
    I guess it's back to the making one from Scratch idea.
  14. Mike14xx

    Mike14xx New Member

    Bachmann has replaced the Spectrum controller and just specifically for all my hornby I bought an HM4000 controller and a step down converter. All my engines-british, german, american, italian, french- they all work beautifully with it, including Acela. That is the part I am still trying to figure out-hornby wont work with american but hornby and bachmann work with british?
  15. Triplex

    Triplex Active Member

    Bachmann makes models for the British market, not just American. That would explain the compatibility.
  16. 60103

    60103 Pooh Bah

    I've never had any problems mixing Hornby (and other British) with North American stock using the same controllers. I don't use 220V controllers.
    At the moment my layout is run by 4 throttles powered mostly by Lionel transformers.

    (had fun at a friends place once. he had an English power pack with a step down transformer. I suggested he try it plugged straight into the 110V. We achieved extremely good slow spped control!)
  17. CNWman

    CNWman CNW Fan

    Wait, what kind of OO?

    Huh? British? HO=OO? What the heck are we talking about? Wasn't OO a scale that Lionel made only 27 things for that were posible more detailed that a G engine
  18. Mike14xx

    Mike14xx New Member

    No your thinking of 0-27. OO is the british equivalent of Ho but instead of being 1:87 scale it is usually 1:72, 1:74, or 1:76 scale.
  19. CNWman

    CNWman CNW Fan

    Now i'm just confused

    Um, I might be wrong, but I'm not thinking of HO. I have a book here Saying that HO actualy is the one from England. All it says is that OO, although you nailde it at 1:76, showed some promise in the late 1930's. Of corse, It's just a book, and I'm only familiar with Gtrain97 ,O (and O-27 somewhat),HO(my scale:D ),and N scales.

    I had OO confused with TT, I'll admit.
  20. jetrock

    jetrock Member

    Part of the confusion, which appears to reappear, is that there were TWO different "OO" scales. The American OO was 1:76 scale with 1:76 scale track. British OO is 1:76 scale with 1:87 scale track, done so small British prototypes could fit the available electric motors. HO was originally British, half of British 1:43.5 O scale (1.25" real-world equals 4'8.5" in British O scale.) American O scale is traditionally 1:48, and runs on 1:43.5 scale track (1.25" real-world equals 5' in American O scale.)

    In case your head doesn't hurt enough, there is a fine-scale British OO that runs on 16.5mm track (4'8.5" at 1:76) and a fine-scale American O (Proto:48) that runs on track that runs on two-rail track approx. 1.17" (4'8.5" in 1/48 scale.)

    I'm not even going to touch narrow gauge...

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