there are a few things wrong here... The M1's and the I1s *may* have shared some connecting rods, but it was *not* the actual valve gear, or at least not all of it. You also probably should have mentioned that although the M1's and I1's shared a similar boiler, the M1's had a large combustion chamber (98 inches). Either way the M1 and I1 boilers were very similar, though *not exactly* the same (The minimum internal diameter of the M1's was slightly larger). All M1 were built to passenger standards carrying chime whistles, not banshees. There were 201 M1's, not 200. The Dual Air Compressors and the Worthington Feedwater Heater were quite significant differences between the M1's & M1a's, but you didn't mention the different cylinder casting with Internal steam pipes instead of External pipes. This cylinder casting also provided an area to mount the pilot truck, so the pilot truck on the M1a's were slightly further forward than on the M1's. The M1a's also had a different arrangement at the front utilizing a 6 point radial blastpipe rather than the previously used Goodfellow blastpipe. And the use of different fire grates. The M1 class was built with round number plates since the keystone number plate didn't exist at the time of construction, but the M1a (built in 1930) came built with Keystones, and Keystones were added to the M1 class after the M1a were built. Also the M1a came equipped with 210F75 tender's during construction, while the M1 were equipped with 110P75 tenders during their construction, before receiving larger tenders later down the line. Most M1a's kept their 210F75s until their retirement, only few received 210F75a/b's (some did), because most of those were given to M1's since they were built small tenders (110P75's, but also received 110P75a's, 130P75's, and the early 210F75's built before the construction started on the M1a's). The PRR also primarily used Bituminous Coal. Not all of the conversions to M1b were in 1946, it happened over a span of a few years. This was not because the firebox expanded by 35 Sq. Ft., because it didn't expand. Rather, the M1a boilers were reaching the end of their lives and being replaced. The new boilers had the addition of firebox circulators, which added 35 Sq. Ft. of heating surface, which was followed up by an increase in pressure to 270 psi. The washout plugs for the circulators are how you tell an M1a from an M1b. Something to mention about the 1st 10 Baldwin M1a's is that they received gold lining on both engine and tender for passenger service (There are some nice images of 6707 floating around). The tenders mentioned in the video are wrong as well. The M1, M1a's, and M1b's were fitted with: 110P75, 110P75a (held more coal, but less water compared to a 110P75) 130P75, 210F75 (there were 3 different types of 210F75, an experimental early version with Commonwealth Friction Bearing Trucks, 9 with Buckeye Friction Bearing Trucks, the resting with Buckeye Roller Bearing Trucks.) 210F75a, (210F75 but with 4 axle Commonwealth Roller Bearing Trucks, moving of the stoker engine onto the tender, welded construction, etc.), 210F75b, and 250P75 tenders. 25 of the 250P75s were built. 21 of the 250P75 went on M1's while the other 4 went onto the K4s, but were later transferred to the M1's. The prototype M1 when 1st built (numbered 4700 at this time, the number was changed to 6699 around 7 yrs later), had a small tender which was designated as a 70P82 (no stoker). And after testing at Altoona and on the road, they realized they needed a larger tender and a stoker, so by 1925 they gave 4700 the stoker and tender used on the I1s (110P82). The 110P tender was kept when the M1 was brought to fleet status, but to standardize it with the K4s and L1s they lowered the M1 footplate height to 76 inches above the rail, so they could be paired with tenders possessing a 75 inch deck height, and kept the stoker, hence the 110P75, instead of 110P82. By 1928, 4700's tender was rebuilt to the standard 110P75. Also, 6755 is preserved, but it is the *only* M1 preserved. The fact that an M1 tender (210F75a) for #5550 is being used is correct, but there was no M1 numbered 6659. The M1 class were numbered 6800 - 6999, with the exception of the prototype M1 which was numbered 6699. The M1a/b were numbered 6700 - 6799. 1100 Tons is quite light for an M1/a/b. In fact, there were accounts of trains weighing up to 11,000 tons being assigned a single M1b (these were slow speed drags though) Also why call it a Baldwin M1 in the title? It was a Pennsy design which the Pennsy ordered Baldwin to build. Baldwin built most of the M1's & M1a's, but not all of them. Information Sourced From Classic Power No 8, No. 109-J - Classification and Description of Locomotives and Tenders (Collection of Bob Johnson), Atterbury's M1 Engines
You do realize there's only one M1 Mountain type left right only one was saved one of the tenders were also say that it's not being used for the T1 project
And I believe you are right about only 1 being preserved. I cannot find anything about any other M1s being preserved other than 6755. I really hope they're not just going off of the image when saying 6759 is preserved because that is an image of it at the New York Worlds fair.
I'm pretty sure they shared some connecting rods but not the actual valve gear, or at least not all of it. The max cutoff on the M1 class was stated to be 78% by Bert Pennypacker. Although the I1sa's got their cutoff raised to 78%. Although tractive effort calculations would not make much sense with 78% soo..
I guess the M1b's must have gotten new boilers as well, to hold the higher pressure? Or were the boilers always supposed to be good for the higher pressure, but it not previously used that way due to limitations in other components?
I believe they did receive all-new higher pressure boilers. The M1b in the Railroad Museum of PA , No. 6755, was originally built as an M1a but was rebuilt with a new boiler and reclassified as an M1b.
there are a few things wrong here...
The M1's and the I1s *may* have shared some connecting rods, but it was *not* the actual valve gear, or at least not all of it. You also probably should have mentioned that although the M1's and I1's shared a similar boiler, the M1's had a large combustion chamber (98 inches). Either way the M1 and I1 boilers were very similar, though *not exactly* the same (The minimum internal diameter of the M1's was slightly larger). All M1 were built to passenger standards carrying chime whistles, not banshees. There were 201 M1's, not 200.
The Dual Air Compressors and the Worthington Feedwater Heater were quite significant differences between the M1's & M1a's, but you didn't mention the different cylinder casting with Internal steam pipes instead of External pipes. This cylinder casting also provided an area to mount the pilot truck, so the pilot truck on the M1a's were slightly further forward than on the M1's. The M1a's also had a different arrangement at the front utilizing a 6 point radial blastpipe rather than the previously used Goodfellow blastpipe. And the use of different fire grates. The M1 class was built with round number plates since the keystone number plate didn't exist at the time of construction, but the M1a (built in 1930) came built with Keystones, and Keystones were added to the M1 class after the M1a were built. Also the M1a came equipped with 210F75 tender's during construction, while the M1 were equipped with 110P75 tenders during their construction, before receiving larger tenders later down the line. Most M1a's kept their 210F75s until their retirement, only few received 210F75a/b's (some did), because most of those were given to M1's since they were built small tenders (110P75's, but also received 110P75a's, 130P75's, and the early 210F75's built before the construction started on the M1a's). The PRR also primarily used Bituminous Coal.
Not all of the conversions to M1b were in 1946, it happened over a span of a few years. This was not because the firebox expanded by 35 Sq. Ft., because it didn't expand. Rather, the M1a boilers were reaching the end of their lives and being replaced. The new boilers had the addition of firebox circulators, which added 35 Sq. Ft. of heating surface, which was followed up by an increase in pressure to 270 psi. The washout plugs for the circulators are how you tell an M1a from an M1b.
Something to mention about the 1st 10 Baldwin M1a's is that they received gold lining on both engine and tender for passenger service (There are some nice images of 6707 floating around).
The tenders mentioned in the video are wrong as well. The M1, M1a's, and M1b's were fitted with:
110P75,
110P75a (held more coal, but less water compared to a 110P75)
130P75,
210F75 (there were 3 different types of 210F75, an experimental early version with Commonwealth Friction Bearing Trucks, 9 with Buckeye Friction Bearing Trucks, the resting with Buckeye Roller Bearing Trucks.)
210F75a, (210F75 but with 4 axle Commonwealth Roller Bearing Trucks, moving of the stoker engine onto the tender, welded construction, etc.),
210F75b,
and 250P75 tenders. 25 of the 250P75s were built. 21 of the 250P75 went on M1's while the other 4 went onto the K4s, but were later transferred to the M1's.
The prototype M1 when 1st built (numbered 4700 at this time, the number was changed to 6699 around 7 yrs later), had a small tender which was designated as a 70P82 (no stoker). And after testing at Altoona and on the road, they realized they needed a larger tender and a stoker, so by 1925 they gave 4700 the stoker and tender used on the I1s (110P82). The 110P tender was kept when the M1 was brought to fleet status, but to standardize it with the K4s and L1s they lowered the M1 footplate height to 76 inches above the rail, so they could be paired with tenders possessing a 75 inch deck height, and kept the stoker, hence the 110P75, instead of 110P82. By 1928, 4700's tender was rebuilt to the standard 110P75.
Also, 6755 is preserved, but it is the *only* M1 preserved. The fact that an M1 tender (210F75a) for #5550 is being used is correct, but there was no M1 numbered 6659. The M1 class were numbered 6800 - 6999, with the exception of the prototype M1 which was numbered 6699. The M1a/b were numbered 6700 - 6799.
1100 Tons is quite light for an M1/a/b. In fact, there were accounts of trains weighing up to 11,000 tons being assigned a single M1b (these were slow speed drags though)
Also why call it a Baldwin M1 in the title? It was a Pennsy design which the Pennsy ordered Baldwin to build. Baldwin built most of the M1's & M1a's, but not all of them.
Information Sourced From
Classic Power No 8,
No. 109-J - Classification and Description of Locomotives and Tenders (Collection of Bob Johnson),
Atterbury's M1 Engines
wow, you must have be around during this time to know so much!
Cool if only I knew anything about trains I would like this better.
Awesome
At least I saw 6755
4:05 Passenger Train.
4:05 I Mean A Freight Train.
That loco was a beast!
There aren't too many 4-8-2 Mountains in the North American continent
Did You See 6755?
Not in person, no
Once you understand what they could do, its understandable. That wheel arrangement of 4-8-2 proved very good at multiple assignments.
You do realize there's only one M1 Mountain type left right only one was saved one of the tenders were also say that it's not being used for the T1 project
Wait a minute that's not right only 1 m1b has been preserved #6755 why did you say 3 and a half and that tender is from a prr j1 not a m1b
Nope the tender is off of a M1
@@brendanstrains9725 oh en.m.wikipedia.org/wiki/Pennsylvania_Railroad_class_M1
And I believe you are right about only 1 being preserved. I cannot find anything about any other M1s being preserved other than 6755.
I really hope they're not just going off of the image when saying 6759 is preserved because that is an image of it at the New York Worlds fair.
He went of the locomotive wiki which isn’t accurate
@eafd2708 noted. I’ll try & avoid using it in the future
If the M1's had the same valve gear as the I1's, does that mean their max cutoff was only 50%?
I'm pretty sure they shared some connecting rods but not the actual valve gear, or at least not all of it. The max cutoff on the M1 class was stated to be 78% by Bert Pennypacker. Although the I1sa's got their cutoff raised to 78%.
Although tractive effort calculations would not make much sense with 78% soo..
I guess the M1b's must have gotten new boilers as well, to hold the higher pressure? Or were the boilers always supposed to be good for the higher pressure, but it not previously used that way due to limitations in other components?
While the psi did increase, I didn’t see anything regarding new boilers. At least in the course of my research.
I believe they did receive all-new higher pressure boilers. The M1b in the Railroad Museum of PA , No. 6755, was originally built as an M1a but was rebuilt with a new boiler and reclassified as an M1b.
They did in fact receive new boilers. These new boilers were also equipped with firebox circulators.