Steamer scale size question

[Jacktal]

This week I've set my hands on a beautiful L-L Heritage 2-8-8-2 Mallet.It is a work of art,almost jewelry I might say,and it runs great.But I was quite surprised to find out that when I put it alongside my Bachmann 4-8-4 Northern,it is barely longer.In fact,their boiler/cab total lengths are almost exactly the same.Was it the same in prototype world or is my 4-8-4 way out of scale size?Or is it the Mallet?I expected the Mallet to be much bigger than the Northern.

[Anonymous]

Good news. The models aren't out of scale. The Northerns came along pretty late in the development of steam power, and the great majority of them had large, long boilers. Northerns were intended on most roads to be dual-purpose engines (freight and passenger). High tractive effort permitted them to start heavy trains; their large drivers allowed high speeds for passenger or fast freight service.

Bear in mind the fact that mallets used steam twice--first in the high-pressure cylinders, and again in the low-pressure cylinders.

[dehusman]

The Reading took 2-8-8-2 boilers and put them on 2-10-2 running gear.

Dave H.

[nfmisso]

During WWII, the AT&SF (Santa Fe) purchased some surplus 2-8-8-2 locomotives from the N&W - teh same model that P2K offers. Santa Fe was very impressed with the performance of the boilers, and had plans to rebuild the locomotives as 4-8-4 after the war. The EMD diesels, and Virginian's offer to purchase the locomotives did in that plan.

The USRA 2-8-8-2 (and its developments throught the N&W Y6b) had boilers and fireboxes similar in size to modern 4-8-4 locomotives. Horsepower is in the range of 5000 to 6000 in both arrangements. The Mallets peaking at 20 mph +/- and the 4-8-4 at 40 to 60 mph.