Jump to content

Talk:Garratt locomotive

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

Merge 0-4-0+0-4-0 with this article

[edit]

Better delete 0-4-0+0-4-0. The K class has it's own entry, and the 0-4-0+0-4-0 article has no real infomation. Very few garratts were 0-4-0+0-4-0 anyway. The contrary argument is that most other wheel arrangements have their own entries, so why not this one?--Michael Johnson 05:25, 13 May 2006 (UTC)[reply]

Merge - the article title has no context and is only two sentences at present. SM247 21:08, 7 May 2006 (UTC)[reply]

Garratt not an Australian

[edit]

I've deleted the reference to Garratt as an Australian, in fact he never even visited Australia. As an Aussie myself, I would love to claim him, but there you go. Don't know where this furphy came from. --Michael Johnson 07:36, 10 May 2006 (UTC)[reply]

From what I know, Garratt was the Chief Inspector (or some similar position) of the New South Wales railways when he came up with his articulating arrangement; I'll see if I can find a citeable source for that if you fancy.
Garratt was contracted by the NSW railways to inspect locomotives being built in the UK for the railways to ensure they were up to quality, specification etc. So he is often (rather mistakenly) referred to as a NSWGR locomotive inspector. He NEVER came to Australia, and most certainly was not born here. And believe me, as an Australian and an admirer of Garratt locomotives I wish I could claim him. There is a web article about Garratt that does claim he was an Australian, unfortunately it has some credence as it is on a Melbourne University site. But it is factually wrong, I have contacted them and we are in the middle of getting it changed. Cheers,--Michael Johnson 03:45, 3 June 2006 (UTC)[reply]

K class

[edit]

Was the K-class garratt the only one with this wheel arrangement? Tabletop 10:34, 19 May 2006 (UTC)[reply]

No. See http://users.powernet.co.uk/hamilton/dimensions.html, plus I'd say that Fairlies are 0-4-4-0T. — Dunc| 10:59, 19 May 2006 (UTC)[reply]
Of course Fairlies were not Garratts - 0-4-4-0 is probably the correct wheel arrangement for them, but that is different from 0-4-0+0-4-0. --Michael Johnson 00:32, 20 May 2006 (UTC)[reply]

Problems with disadvantages

[edit]

I have a problem with the disadvantage section. It strikes me that most of the "disadvantages" described for the Western Australian and New Zealand sections are actually operating or engineering issues with the railways concerned. As it stands there appears to be undue emphisis on disadvantages, giving the casual reader the impression that the Garratt might not be a particularlly sucessful design. I'll leave this note here for a couple of weeks for comments, and then if nobody has an opinion rewrite that section. --Michael Johnson 00:34, 4 July 2006 (UTC)[reply]

Yes, I agree. They are not so much disadvantages of the Garratt concept, rather they are problems with the railways, or in the case of the ASG, problems with specific implementations. jtc 02:07, 4 July 2006 (UTC)[reply]

Might it be worth clarifying the reasons behind the sparse usage of Garratts in Great Britain, a la the references to the NZR and Western Australian Garratts? It seems to me that the present remark on the situation might leave readers with the impression that the Garratt was simply not the sort of engine British railway companies wanted; of course, getting too deep in specifics on individual classes is something of a minefield, so I'll await any other opinions. 86.132.226.171 04:12, 3 September 2006 (UTC)[reply]

You mean besides the point that British freight trains were in general short collections of unbraked wooden four-wheeled wagons, operating over routes with broad curves with slight grades? Hauled in the main by 0-6-0 tender and tank locos? In a country that didn't adopt 2-8-0's as a standard freight type untill about 30 years after they had become obsolete elsewhere in the world? Well I hope my change comveys that a little more politely ...:-) --Michael Johnson 03:15, 4 September 2006 (UTC)[reply]
By the way, would I be right in saying that Garratts were the only articulated used by British standard gauge railway companies? --Michael Johnson 03:57, 4 September 2006 (UTC)[reply]
So far as I'm aware, that was the case; it'd make sense, since (for the reasons cited above) articulation was largely unnecessary on british standard gauge metals; the LMS/LNER Garratts were built for their brute strength on a half-decent axle loading, rather than turning ability, so far as I can deduce. It's ironic, in a way, that British firms like Kitson and Beyer, Peacock should've been so under-endowed with British orders. I'll check up, however, and edit if necessary. 86.141.152.84 22:15, 4 September 2006 (UTC)[reply]
And don't forget North British did a nice line of fair-sized Mallets untill BP put them out of that business with Garratts. --Michael Johnson 23:06, 4 September 2006 (UTC)[reply]
And let's not forget the "Modified Fairlie"! "What bandwagon? Nae, nae, we werenae jumpin' on tha' thair bandwagon, ya sassenach Mancunian!" Anyway, from what I can tell (looking through my limited stuff) no articulated type other than Garratts were ever employed by any British railway company, possibly excepting some very early Fairlies that were out of commission by the early 20th century. 86.133.226.230 01:56, 5 September 2006 (UTC)[reply]

AD60

[edit]

Also, while I'm awake and functioning, I've edited out the statement that the AD60s were the most powerful locomotives operating in the Southern Hemisphere. At no point in their existence, to my knowledge, did these engines qualify for such a title; they were exceeded in Tractive Effort by the SAR GL class, the EAR 59th class and the RR 20th/20A class, to my recollection from memory. The AD60s, in comparison, developed 52,700lbs' T.E. at 75% boiler pressure (or, in the AD60++, 56,020) against 78,650lbs for the GL, 73,500lbs for the 59th and 61,176lbs for the 20th/20A class(es). 86.132.226.171 04:24, 3 September 2006 (UTC)[reply]

Good edit. I knew this, but never got around to pulling out the references to correct it. --Michael Johnson 03:15, 4 September 2006 (UTC)[reply]
No trouble. Would you happen to know why, in Durrant's approximate words, "their [the AD60s] original low axle-loading requirement ensured that a great deal of their tractive effort was nullified by deadweight"? 86.141.152.84 22:15, 4 September 2006 (UTC)[reply]
I presume the problem is that the AD60 was designed for branch line use, thus the axle loading requirement, but found their major use in main line mineral traffic. Laterly they were modified (?) to give higher tractive effort, with a higher axle loading. --Michael Johnson 00:30, 20 November 2006 (UTC)[reply]

My personal understanding is that the EAR 59th has a tractive effort of 83,350 lbs. This is backed up by the definitive works on Beyer-Garratts " Beyer, Peacock, locomotive builders to the world by Hill ISBN 898432 05 8 page 255 paragraph 1 User Trevor Heath December 2007

The difference lies in the efficiency constant used for the tractive effort calculation. Tractive effort is computed with the formula (D²x S x P x E)/(W x 100)x N = T.E., where D = cylinder bore, S = piston stroke, P = working pressure, E = constant of efficiency (the assumed percentage of the steam pressure doing useful work), W = wheel diameter in inches, and N = the constant for the number of cylinders (multiply by 1.5 for three, 2 for four, 3 for six, etc).

From this, we can therefore compute the respective tractive efforts at 75 and 85% boiler pressure. For the 59th class we have:

73,543lbs @ 75% boiler pressure, or 83,550lbs @ 85%, versus for the GL class:

78,650lbs @ 75%, or 89,137lbs @ 85%. If you don't trust my working, by all means check :). Anyway, upshot is that you're right, but not right; the trouble here is that Beyer, Peacock & Co. used the 75% constant to calculate tractive effort, while the British standard is 85% (and the American, apparently, 65% - go figure, folks). Hills, I believe, is using the British constant, while Gavin Hamilton's brilliant site [1] uses Beyer, Peacock's 75% constant, as do all Beyer, Peacock drawings etc. that I've come across.

In short, the GLs win. But not by much!--1966: End of an Era. (talk) 21:13, 22 March 2008 (UTC)[reply]

ASG

[edit]

I dont know if being away from this article for so long - but I was sure there was a better explanation of ASG's in Australia the article - it seems to have been edited in such a way as to not be understood what they were about. I am sure there was something about the ASG's on the Emu Bay as having a reasonable run. Also the "early Tasmanian garrats" - no class given seems to vague. Just an observation SatuSuro 02:19, 9 September 2006 (UTC)[reply]


Apologies, I now realise that this has been put in the separate ASG article - but still think an expansion about the context is worth putting in the main article. SatuSuro 02:33, 9 September 2006 (UTC)[reply]

'American rail companies considered the Garratt's coal and water capacities unequal to their requirements.'

[edit]

It would be good to have some context for this- what is the capacity of a Garratt relative to other designs and what were the requirements of American rail companies? Thanks for an interesting article. Andy Duncan.

This is one reason often given, the other that Americans were uncomfortable with locomotives with variable traction weight. Of course both these objections could be easily overcome by using water tenders, as occured in South Africa. So it is more of an excuse than a valid objection. I think the reason is more complex, and relates to timing. The Garratt design started to hit its stride in the 1920's, just as the American railways were getting into superpower designs. The depression years of the thirties and the war years of the fourties were not the time to experiment with new types of motive power. And the type of railways where the Garratt shined, lightly laid branch lines, and mountainous routes, were often the last to get new motive power anyway. By the late fourties and the fifties, when truely huge Garratts were being built (some of the African narrow gauge designs, if built to standard gauge proportions, would have dwarfed the UP Big Boys) the American railways were moving fast into dieselisation. However there were some truely giant Garratt designs proposed for the US at this time, for instance combining with a Mallet to make a 4-8-8-4+4-8-8-4. But the above is "original research" so has no place in the article. --Michael Johnson 00:22, 20 November 2006 (UTC)[reply]


Garratt lookalikes

[edit]
South African Union Garratt

I've removed the photo of the Union garratt because of course it is not a proper garratt. However a section on garratt "ripoffs" is a good idea, so I'm storing the link here until the section is written. --Michael Johnson 02:20, 15 December 2006 (UTC)[reply]

I've made a small start on a section for this; what I've put isn't much, but hopefully others can build on that when I forget/lose motivation/suddenly have no time. I didn't think it particularly necessary to cover the major competitors to the Garratt where they had an article in existence, but if anyone feels it productive to add sections on the contemporary competitors (the Kitson-Meyer, Modified Fairlie and Golwe) and their impact relative to the Garratt, it might be an idea. Just wanted to avoid unnecessary inter-article tautology :) --MancMezJ (talk) 06:59, 23 March 2008 (UTC)[reply]

Australia-centric and class info

[edit]

I note a lot of editors on this page (including myself) are Australian. While we love our Garratts can we keep it in mind that Garratts were far more significant in other parts of the world, and we should be careful this page does not become the "Aussie Garratt" page! --Michael Johnson 00:12, 18 December 2006 (UTC)[reply]

To keep up my Kiwi credentials, perhaps it should be ANZAC Garratts? Although we only had one class here in NZ, and they didn't last very long. I think this comes down to an underlying Wiki problem - if you have lots of editors interested in a particular subject, or a sub-set of a subject, then there appears to be more emphasis place on that subject. This is probably why this article doesn't have much on Southern African Garratts, as there generally aren't as many editors for Southern Africa. --Lholden 00:53, 18 December 2006 (UTC)[reply]
Interesting that - my understanding is that the south african garratts had the longest existence - and the larger number than australia ever had? is that true? SatuSuro 01:00, 18 December 2006 (UTC)[reply]
On my counting South Africa had about 355 Garratts of 13 different classes in 3'6" gauge, and 53 of 5 differnt classes of 2' gauge. Remember this is only one country. Many other African countries had large numbers of Garratts, too. --Michael Johnson 01:41, 18 December 2006 (UTC)[reply]
I think due to fuel shortages Zimbabwe is making use of their fleet now also, although I understand it's pretty hard to go there and take pictures... --Lholden 02:30, 18 December 2006 (UTC)[reply]

Let's get the article standard up! - citation tags

[edit]

This is developing into a good article. Let's take it up to the next level, with inline citations. I've gone through and put citation tags at appropiate points, not because I dispute them. Rather by putting references in we can aim to bring this article up to featured article status. Most of them will be easy, some more difficult. If you have a citation but can't work out Wikipedia's formatting, don't worry. Put it in as best you can and someone will fix it up latter. --Michael Johnson 00:43, 23 February 2007 (UTC)[reply]

Yes, I agree. However, there are five citations already. One of them points to chapter and verse in Tom Rolt's book, so pick up the book and go straight to the page. The other four just point to Durrant and in effect say "Durrant says so but you will need to read the book if you want confirmation of the details" and that is very little help to the reader, especially since Durrant is the major source. NoelWalley 08:15, 23 February 2007 (UTC)[reply]
The Rolt citation is what we should aim for, and the others will need to be fixed as part of this process. BTW I'm not suggesting it all needs to be done tomorrow, but if editors can do bits and pieces as we go, then it will all start to come together. --Michael Johnson 23:10, 23 February 2007 (UTC)[reply]


Article contradicts the citation in the intro

[edit]

In the intro, it says "however no railway that possessed Mallets and purchased Garratts ever purchased another Mallet" -- in the "Garratts around the world" section it says that the Russians, after purchasing a Garratt and not replicating more of them because of maintenance and politics, went on to experiment with Mallets. Karlkatzke 21:50, 4 May 2007 (UTC)[reply]

Corrected --Michael Johnson 01:50, 2 July 2007 (UTC)[reply]

Only one regulator?

[edit]

Another disadvantage is that both power units are controlled by one regulator, thus if one power unit slipped the steam to both was reduced as the driver tried to control the slip.[citation needed]

Surely it would not be rocket science to build a double-regulator if this were really a problem?

Tabletop (talk) 08:18, 4 April 2009 (UTC)[reply]

Yes, I'd agree. And as we have been looking for a source for some time perhaps it is time for that to go. --Michael Johnson (talk) 08:50, 4 April 2009 (UTC)[reply]

Recent edits

[edit]

I've removed three recent specific good faith edits. The reason is the first two were class-specific issues that were properly dealt with in the articles on those classes. The third seemed to be more of an enquiry than additional infomation, one that could have been answered by reading the article, specificity the section on "The first Garratt". --Michael Johnson (talk) 22:55, 4 December 2009 (UTC)[reply]

Safety in tunnels undue weight

[edit]

A section has recently been added / come to my notice that seems to be WP:UNDUE. It claims that articulated locomotives are unsafe in tunnels, owing to a risk of trapping the crews after an accident. There are several problems with this:

  • It's based on just one fatal accident, by asphyxiation. It's also unreferenced, but I consider that a minor point of WP:V, not factual accuracy in the general sense. I don't dispute the accident happened.
    • This accident was caused by the steepness and narrowness of the particular tunnel, which already had a serious history of such accidents without Garratt involvement.
    • There is no indication that the Garratt caused the problem. The claimed "lack of escape route" problem doesn't seem to have applied, as the crew stayed on the footplate and didn't try to escape.
    • Double headed locomotives (working that weight, over that incline) would have just the same problem.
  • There's no indication that "hot cylinders block escape through tunnels" any more than smoke, boilers or other parts of non-articulated locomotives.
  • There's no indication that "Garratts block escape through tunnels" any more than any other design.
  • There's no indication that "articulated locomotives block escape through tunnels" any more than any other design.
The editor adding this section has also tried to add it to the Fairlie article, despite there being no such accidents with Fairlies, or Fairlies having such large cylinders so close to the loading gauge.

I see a historical reason to include a note on the accident, but not to generalise this into a systematic fault of Garratts (or even that class of large narrow-gauge Garratt, without some good supporting reference). Thoughts? Andy Dingley (talk) 17:11, 18 January 2010 (UTC)[reply]

Advantages

[edit]

When swinging around curves the boiler and cab unit move inward like a bowstring in the bow of a curve and this reduces the centrifugal force that would overturn a normal locomotive and which in turn permits faster running

The centrifugal force is a function of speed and radius. The change of the radius is minimal. What I think, the writer did misunderstand, basically it must be considered, that forces are transferred from the boiler bridge to the engine frames on the articulation points only. Therefore the horizontal position of the center of gravity of the boiler bridge - relatively to the rails - has no influence on the statics. I think, the real advatage of Garrett design is the vertical position if the center of gravity. It allows a low center of gravity even if the boiler diameter is much bigger than the track gauge.--Helmigo (talk) 11:40, 31 July 2011 (UTC)[reply]

Spanish Garratts

[edit]

''''''Hey, folks! What about SPANISH garratts? : 38 units, 7 types (one speciffically buid for passenger haul), 7 companies , 3 gauges (cape, metter, iberic broad). One broad gauge in working order (and now, one of the very few spanish steam locomotives in use), another in restoring ...etc''''Bold text Bold text' — Preceding unsigned comment added by 188.77.168.30 (talk) 09:59, 20 August 2011 (UTC)[reply]

Added. – Iain Bell (talk) 16:00, 20 August 2011 (UTC)[reply]

Two engines

[edit]

I'm rather uncomfortable with the text referring to "two engines". 99% of the people coming here for information -- aren't they our customers? -- think an "engine" is a boiler + undercarriage and however pure this terminology may be to insiders, it utterly confuses the 99% who are looking for information here.

I'll leave this a wqeek or so but unless anyone has an objection I'll revise it a little. Afterbrunel (talk) 20:29, 11 August 2012 (UTC)[reply]

[edit]

Hello fellow Wikipedians,

I have just modified 2 external links on Garratt. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 04:14, 11 October 2017 (UTC)[reply]

Changed the "centre" to "ceneter"

[edit]

I decided to change the "centre" to "center" because mostly, Wikipedia consists of american users. — Preceding unsigned comment added by Patrick901 (talkcontribs) 23:51, 1 January 2021 (UTC) also find my bots editing stuff on wikimedia — Preceding unsigned comment added by Patrick901 (talkcontribs) 23:54, 1 January 2021 (UTC)[reply]

@Patrick901: "because mostly, Wikipedia consists of american users According to whom? This is a global encyclopedia, not an encyclopedia just for Americans. Note also that per MOS:TIES, an article subject with ties to a specific nation, like a steam locomotive invented by a British guy, would appropriately use British English. Cyphoidbomb (talk) 01:03, 2 January 2021 (UTC)[reply]
@Cyphoidbomb: Seconded! Hence the "Use British English" tag at the beginning of the article. I wonder whether Patrick901's comment "also find my bots editing stuff on wikimedia" mean this wasn't a unique example of inappropriately imposing US spelling? SCHolar44 🇦🇺 💬 at 03:08, 2 January 2021 (UTC)[reply]

Disadvantage

[edit]

Someone reverted my edit about how garratts have heavier axle loads than a contemporary articulated locomotive of similar weight; I mean mallets have more wheels under them throughout then garratts so the weight is more evenly distributed, I don’t see why someone would remove that. I can make a diagram if someone still can’t understand. — Preceding unsigned comment added by 2601:245:C101:9C70:E561:E3C:F9FD:BED9 (talk) 23:17, 2 February 2022 (UTC)[reply]

Please consider the core content policies of verifiability and no original research. --Redrose64 🌹 (talk) 22:24, 3 February 2022 (UTC)[reply]
It's not original research, it's basic intuition. It's even referenced in the quote from O.S. Nock in the advantages section : "This [the Mallet] was so designed to provide a very large engine unit, to be managed by a single crew, but to spread the dead weight over many axles and thus avoid excessive loads on the track and under-line bridges..." — Preceding unsigned comment added by 2601:245:c101:9c70:c955:6392:6da2:dea6 (talk) 22:47, 6 February 2022 (UTC)[reply]
Basic intuition does not satisfy the verifiability policy. --Redrose64 🌹 (talk) 22:58, 6 February 2022 (UTC)[reply]