I understand that the Lima Super Power 2-8-4 prototype and the T&P 2-10-4s used locomotive to tender drawbars connected off of the trailing truck instead of the locomotive frame. Were there any other locomotives that used this type of connection between locomotive and tender?

Thanks,

Smokebox

How long did either last, 2-8-4 prototype and the 2-10-4s?

Almost sounds like an accident waiting to happen. After all there is a lot of force on that drawbar.

Was the drawbar literally mounted to the trailing truck, or did it share the same mounting boss as the truck?

Rich

> I understand that the Lima Super Power 2-8-4
> prototype and the T&P 2-10-4s used
> locomotive to tender drawbars connected off
> of the trailing truck instead of the
> locomotive frame. Were there any other
> locomotives that used this type of
> connection between locomotive and tender?

> Thanks,

> Smokebox


rcizik5519@earthlink.net

> How long did either last, 2-8-4 prototype
> and the 2-10-4s?

To the end of steam.....the design was used by the early Lima 2-8-4s on ICRR, B&A, B&M, Erie; and on the T&P Texas-types. T&P 610 operated in the 1970s.

> Almost sounds like an accident waiting to
> happen. After all there is a lot of force on
> that drawbar.

They did tend to climb the rail when backing up on curves......

> Was the drawbar literally mounted to the
> trailing truck, or did it share the same
> mounting boss as the truck?

The truck was mounted to the rear of the engine's frame by a pin on the front of the truck, and the drawbar to the tender was mounted (again, via a pin) to the rear of the truck.

The ashpan was carried on the truck, and this was supposed to give greater ashpan capacity (an often-overlooked factor in long-distance running-- not just tender capacity mattered!). In practice, it allowed too much cold air into the firebed.

The 1925 Super-Power locomotives were very good, but the 1934 versions (the Van's Berkshires) were great.

Every Lima four-wheel-trailing-truck engine in the 1930 Cyclopedia has this arrangement. The actual frame of the locomotive ended at the throat sheet of the firebox, and the trailing truck was it to the rear of the locomotive, sort of like the front engine unit of a mallet in reverse. The centering rockers at the rear of the truck were the only support for the rear of the firebox, which was a major disadvantage of this design in that the firebox had to take on all of the vibration, shock, and the centering stresses for the truck in addition to its primary job of containing 240+ PSI steam. I imagine that leaking boiler seams were a constant problem for these engines. Later generations of Lima super-power reverted back to a standard type frame, and I believe that T&P 610 in the only one extant.

From LimaÂ’s ad in the 1930 Cyclopedia:

“Four Wheel Articulated Trailing Truck

Not only does the FWATT make it possible larger grate area and firebox volume but it also eliminates the old complaint of inadequate ash pan and restricted air opening which limit the efficiency of existing power. The ash pan of the Super-Power steam locomotive is carried directly on the FWATT. It has one cubic foot capacity for each square foot of grate area. The self cleaning hoppers are 40” wide. The ash pan air opening is 116% of the air opening through tubes and flues. This ash pan construction provides plenty of air for proper combustion in the firebox.

The FWATT greatly reduces track stresses, improves the riding qualities of the locomotive, and keeps the drawbar pins near the center of the track.”

This photo from the Cyclopedia shows the arrangement clearly due to the lack of an ash pan on this oil burning engine.



Strasburg Rail Road

kelly@strasburgrailroad.com

> Every Lima four-wheel-trailing-truck engine
> in the 1930 Cyclopedia has this arrangement.
> The actual frame of the locomotive ended at
> the throat sheet of the firebox, and the
> trailing truck was it to the rear of the
> locomotive, sort of like the front engine
> unit of a mallet in reverse. The centering
> rockers at the rear of the truck were the
> only support for the rear of the firebox,
> which was a major disadvantage of this
> design in that the firebox had to take on
> all of the vibration, shock, and the
> centering stresses for the truck in addition
> to its primary job of containing 240+ PSI
> steam. I imagine that leaking boiler seams
> were a constant problem for these engines.
> Later generations of Lima super-power
> reverted back to a standard type frame, and
> I believe that T&P 610 in the only one
> extant.

> From LimaÂ’s ad in the 1930 Cyclopedia:

> “Four Wheel Articulated Trailing Truck

> Not only does the FWATT make it possible
> larger grate area and firebox volume but it
> also eliminates the old complaint of
> inadequate ash pan and restricted air
> opening which limit the efficiency of
> existing power. The ash pan of the
> Super-Power steam locomotive is carried
> directly on the FWATT. It has one cubic foot
> capacity for each square foot of grate area.
> The self cleaning hoppers are 40” wide. The
> ash pan air opening is 116% of the air
> opening through tubes and flues. This ash
> pan construction provides plenty of air for
> proper combustion in the firebox.

> The FWATT greatly reduces track stresses,
> improves the riding qualities of the
> locomotive, and keeps the drawbar pins near
> the center of the track.”

> This photo from the Cyclopedia shows the
> arrangement clearly due to the lack of an
> ash pan on this oil burning engine.

I believe you'll find that most if not all of these FWATTs were booster trucks and contributed to the tractive effort of the locomotive. The one
shown appears to be a booster truck.
Experience with todays diesels would indicate that the FWATTs might have a jackknifeing tendency when making a heavy shove backwards. I believe the rule with the diesels is that where there are more that 3 units, all but the three against the train are isolated.
Jim

rrfanjim@charter.net

> To the end of steam.....the design was used
> by the early Lima 2-8-4s on ICRR, B&A,
> B&M, Erie; and on the T&P
> Texas-types. T&P 610 operated in the
> 1970s.

> They did tend to climb the rail when backing
> up on curves......

> The truck was mounted to the rear of the
> engine's frame by a pin on the front of the
> truck, and the drawbar to the tender was
> mounted (again, via a pin) to the rear of
> the truck.

> The ashpan was carried on the truck, and
> this was supposed to give greater ashpan
> capacity (an often-overlooked factor in
> long-distance running-- not just tender
> capacity mattered!). In practice, it allowed
> too much cold air into the firebed.

> The 1925 Super-Power locomotives were very
> good, but the 1934 versions (the Van's
> Berkshires) were great.
The T&P rebuilt some of the 2-10-4 with cast frames and normal trucks and lighter rods after the war. They were going to do them all but went to diesels instead. The ones that were updated showed fewer leaks in firebox and less staybolt s brakeing. I don't have time to look it up but it was reported in railway age or railway mech .eng. of about 1945 to 1947. bb