The B&O T4 Mountains were originally built for the Boston & Maine by Baldwin and were the largest Mountains ever made.
A little T3 info;
Most B&O fans know that the railroad always carried a lot of debt and was usually short on cash. So when WWII started the B&O was stuck with a set of steamers that were close to 20 years old. We are talking about P7s, Q4s, and S1 Big Sixes. Engines such as the E27 Consolidations, EL 2-8-8-0s, Q1, Q7, Q3 Mikados, and P1-P5 Pacifics, were at least 5 years older than that. The B&O already knew that diesels were the way to go but 4 ABBA sets of FTs were all they were going to get. And there was a need for engines with better steaming capacity for fast freights in the Midwest, and express service over the West End to Grafton and Sand patch to Pittsburgh.
So once the B&O established that souped-up Q4s with 70 inch drivers were not going to cut it in Ohio and Indiana, they decided on the home built option to meet their need. Everyone that has B&O Power can see just what the B&O did to make a T3. Boiler shells from pre WWI P1 and Q1 engines were used as a starting point. A new boiler course was added to make the engine longer. All T3s had every modern appliance available in the last full decade of steam. These included Worthington Type SA feedwater heater pumps, B&O Type R superheaters, combustion chambers, siphons, circulators, lateral motion devices, Alco G-1 reverse gear, and Mod H.T. stokers. All had single guides and Baker valve gear. All of the T3s were built with new cast steel frames with integral cast cylinders from General Steel Casting Corp. All had 27x32 inch cylinders, 70 inch drivers, 65,100 pounds of tractive effort, 230lbs psi, and a cylinder horsepower of 2990. They had Westinghouse air-signal whistles and steam-heat lines. So even those these were classed as rebuilds, they were over 90% new. They were the LAST engines built at the Mt.Clare shops in Baltimore and the LAST 4-8-2s built in the US!
The first group, class T3, were built beginning in late 1942. Engines 5555-5557 were the first 3 engines completed before the New Year. Engines 5558-5563 were built in 1943. These engines all had friction bearings on all axles. They were also built with Vanderbilt tenders that had 4 wheel trucks and carried 15,000 gallons of water and 26 tons of coal. One T3a engine was built in 1943 and it had roller bearings on all axles. Here is a shot of how the original engine and tender looked.
http://www.rr-fallenflags.org/bo/bo-s5565amm.jpg
Engines in the T3b series included 5565-5567, built in 1943, engines 5568-5574, built in 1944, engines 5575-5581 built in 1945, and engines 5582-5584 built in 1946. All had friction bearings on all axles. And all of these engines were suppose to have new large rectangular tenders that carried 20,000 gallons and 25 tons. But this isn’t the only tender mystery. Here is the way most of the T3bs looked, most of the time.
http://www.northeast.railfan.net/images/bo5569s.jpg
Finally, the last group of T3cs, numbers 5584-5591 built in 1947, and numbers 5592-5594 were completed in 1948. The only difference on these engines is that they had roller bearings on all axles except the drivers. They all looked basically like 5569 pictured above.
These were the engines that the B&O used to compete with the NKP Berks on the Akron and Chicago Divisions. Some of these were still in storage as late as 1961. Besides the EM-1, these were the most modern steamers the B&O ever ran.
David Morgan had some interesting things to say about the T3 in the "In Search of Steam, vol 3: 1955, issue of Classic Trains, a special edition mentioned the T3. He wrote,
"B&O's T3 is an interesting machine. the road has 40 of them, all rebuilt at Mount Clare Shops, Baltimore, during 1942-1948 from older 4-6-2s and 2-8-2's. As Hasting's photos indicate, a T3 looks better coming at you than broadside. For improved steaming and accommodation of larger drivers and a 4-wheel guide truck, the old boilers were lengthened. This upset the natural contour of the barrel and made of the T3 - from sandbox forward, an anemic looking animal indeed. All of which may be excused on grounds that the T3 was a child of war. She was born when the War Production board sliced a diesel order from 23 to 9 locomotives, and she was a bargain. To shop the Mikes would have cost $15,000 each and increased the gross tractive effort by zero. The rebuilds cost $64,000 each and increased cylinder horsepower from 2128 to 2990. Equivalent new power would have cost $150,000 apiece.
And a T3 will perform. I used to admire sitting in the dome of The Capitol on evenings when a T3 would doublehead with the diesel units out of Cumberland and up Sand Patch. They appeared to be racy, tireless performers...And nothing we saw at Willard abused that notion".
