What steam engine had the tallest drive wheels?
Deutsche Reichsbahn class 05 of 1935 had drivers of a diameter 2,300 mm, that´s over 90 1/2 inches.
!(http://i122.photobucket.com/albums/o263/Daneelo/Monday Train Blogging/BR05.jpg)
I am not sure whether she had the tallest drivers of all, I bet, some of the single-wheelers of the late 1800´s in the UK had even taller drivers.
This beauty, built in 1893, was descriptively named the “7ft 6in Single” - class of the LNWR. Must have been quite a job to get those wheels balanced.
This one beats all of them:
Driver diameter is 8´ 6"!
Yeah, the English single-drivers from around 1860 are the ones to check on. Several (?) had 96 inches and a couple of short-lived experimentals were taller than that.
…What was the point to see how big of drivers they could fit to an engine…? Were they just trying to move a few passenger cars…
Certainly would have had a shortage of torque for any amount of grades…or even pulling loads of freight. {After the inertia of the spinning wheels was “drained”}.
And back in the early era of these wheel giants, the track surely wasn’t the best for any “great” speed to take advantage of these "hi geared’ monsters…
Increasing driver size put the engine into high gear, so to speak. The idea was to get the maximum travel distance out of each cycle of time between the stopping and reversing of the pistons. Although this was in the primitive era, the track was good enough for very high speed in many cases.
Perhap the goal was less RPM for a given track speed, hence a slower piston speed and valve event rates, and less dynamic forces in the pistons and rods, etc. I believe that lubrication of the cylinder walls left a lot to be desired back then - it was the ‘tallow’ (rendered hog fat) of ‘tallowpot’ fame, poured in when the engine was drifting’ - so it was none too good.
A lot of the mechanical aspects of those huge wheels could be compensated for or equalized by adjusting the location of the crankpin between the wheel center and rim - x 2 ==> piston stroke - and then the cylinder diameter. All other characteristics being equal, the steam consumption rate could have stayed about the same - a much larger cylinder, but a much lower RPM - and hence the power output would have been about the same. Kind of like trying to get your car into motion in 3rd gear instead of 1st, I suppose . . . [:-^]
- Paul North.
Without current research, the point was that considering the capabilities of metallurgy, counter-balancing and lubrication technology of the period the slower the machinery (pistons, rods and levers and journal bearings, etc) operated, the greater the speed for the greater the distance.
THe highest driver-ed engines probably had a bit more torque (tractive effort) than needed to haul its tender.
The high-wheelers on the era’ s track impose the fewest and smallest impacts to the track structure when compared to lower drivered engines at similar speeds.
High drivered engines, especially in the early days? One answer, and one answer only: SPEED. Those high drivered engines, especially like the one Sir Madoq posted could run like rabbits. The downside (and isn’t there always one?) was they were very slippery on the starts. The concept was tried here in the 1840’s on the Crampton engines and given up pretty quickly.
And the winnah is…
Bristol & Exeter Ry. Pearson Single 4-2-4T ‘Nine footer.’ 108 inch drivers.
Built to Brunel gauge, there was room enough between the boiler and the single flangeless driver on each side for all the propulsion machinery. The Wikipedia photo of #44 appears to have drivers at least as tall as the boiler top. The drivers were flangeless, and the treads were quite wide. They were quite speedy, which must have been fun for the engine crew riding in a roofless, low-side cab!
Chuck
…If these “monsters” were built for speed, does anyone have or have seen…any speed records set by these type of engines…?
Such as a traditional steamer did here in this country in the early 1900s. I don’t have the info in front of me now, but it’s in one of my picture books here…Believe the speed was something like 127 mph.
NYC 999 was a one-off 4-4-0 that was built with 86" drivers (smaller than most of the examples above but still pretty tall) and reached an alleged 112.5 MPH in 1892. The claimed record of 127 MPH was run by PRR 7002, a conventional E-6b 4-4-2.
NYC’s 4-4-0 999 with 86.5" diameter drivers at 112.5 MPH, perhaps ? See:
http://en.wikipedia.org/wiki/New_York_Central_and_Hudson_River_Railroad_No._999
Tomikawa’s answer rings true as about right to me, without researching it further.
- Paul North.
The 999 did not hold the record for the tallest drivers, but it was, without a doubt, the best looking steam locomotive ever built. The 999, as it exists today, has lost its original fabulous appearance because it has been rebuilt with smaller drivers, among other alterations.
Well, I dug into my “library” here in the home office and pulled out my 1944 booklet…“Pennsylvania Railroad”…It’s primary a picture book.
Some comments with the photos of the Pennsy passenger train:
Worlds fastest train now, or in 1905. {Remember this is 1944}…
On June 12, 1905, The Pennsylvania Special, predecessor to the Broadway Limited went 3 miles in 85 seconds. Roughly, 127.2 mph {the mph, my figure}.
It was pulled by a E-2 Atlantic…4-4-2…{The rear wheels look strangely large…but smaller than the drivers of course…but they are spoked…??
It appears to have at least 4 passenger cars on it. Engine number appears to be: 7373.
The photo was with it standing in: Englewood Station, Chicago. [2c]
Another high-wheeled beauty:
http://chuckzeiler.rrpicturearchives.net/showPicture.aspx?id=1874260
Here is another shot of #999 before they made it look ordinary:
http://4.bp.blogspot.com/_bgDRKmnIMvo/RcXgUGh491I/AAAAAAAAAO0/hfdNFsus0vU/s1600-h/1836-0.jpg
**Quentin:(**Modelcar) wrote the following post on Monday, February 27, 2012
[snip]"…Worlds fastest train now, or in 1905. {Remember this is 1944}…
On June 12, 1905, The Pennsylvania Special, predecessor to the Broadway Limited went 3 miles in 85 seconds. Roughly, 127.2 mph {the mph, my figure}.
It was pulled by a E-2 Atlantic…4-4-2…{The rear wheels look strangely large…but smaller than the drivers of course…but they are spoked…??[snip]
Quentin: Looking at the PRR type E-6 it does not look like a ‘speedster’ but a ‘solid, built to work’ type locomotive.
Here is a link to a photo of a PRR Type E-6:
http://www.germansteam.co.uk/tonup/tonup.html#460
Bear in mind the Specific Locomotive that went 127.2 mph was 7002 which was reported to be a Type E-6 b the picture on the link is a Type E-6s and apparently the only(?)E-6 Type resides at the Pennsylvania RR Museum at Strasburg. It is the “Lindbergh Engine” #460. ( link contains some fairly interesting info on the E-6 type.)
There’s always been a bit of controversy concerning the Pennsy’s claim of 127.2 mph for the 7002. Supposedly lack of creditable witnesses and “iffy” timekeeping. Did it really go that fast? The Pennsy said it did. At the end of the day it really doesn’t matter, no-one at the time of the turn of the 20th Century was seriously considering running trains that fast on a regular basis anyway.
This does beg the question, though, as to what the tallest drivers were in regular service. I would argue that the 2-2-2’s already cited were from a time when they were still trying to figure out what worked, and worked well (as well as what didn’t work).
They may have worked, and have been in regular service, but the arrangement didn’t survive into the “modern” steam era like even the 4-4-0 did.
Early railroad publicity speed records may be somewhat in doubt as to their accuracy, but I would speculate that there was probably faster running and more of it in the circa 1900 era than in the modern era of steam and dieselization. They had rules and speed limits back then, but the companies tended to forgive fast running to make up time as long as the engineer could pull it off without any trouble.
CB&Q and the B&MR had some very fast 4-4-2s. They are detailed in BURLINGTON BULLETIN No. 44, where it says that these locomotives were said to go just as fast as any man wants to run them. And engineers were reminded that it was not necessary to make up all the lost time before they reached the first station out of the terminal.
It averaged 69 mph from Crestline to Fort Wayne, but for some reason they ran thru Lima at 120+ mph. They must have been doing a lot of 50 mph on the rest of the trip.
In 1902 PRR found the best they could get out of an E2 (like the 7002) was 95-96 mph with zero cars on a very slight descending grade.