>> I have followed the thread about the striping by the
mars light on Q E-units. I probably misread, but I
seem to recall an implication that these were actual
grilles. If so, what would be their use, given their
location on the locomotive? <<
There's a mis-understanding here. The original flanking panels on the E-5s were
solid, etched, stainless steel plates, screwed on. In later years, this became
semi-handy, as the plates could be used to conceal the front-of-unit MU sockets
which had been retrofitted. Removing and replacing the plates became tedious as
the E-5s were relegated more and more to booster positions, so the plates were
removed and the "grills" just painted over the MU doors. They *never* masked an
actual air intake.
>> When the UP launched its series of City streamliners,
it used what were known as "turret cab" diesels with
large automobile-type grilles in the front. With the
crew so high off the ground, I somewhere got the idea
that the air brought in from the grilles actually went
through to the engine room and was used for cooling
the diesel motors. Am I correct? Or were there large
automobile-type radiators behind the grilles, like in
cars? <<
Adequate cooling became an in-service problem for many early diesels. On the UP
turret-cabs, the air *did* come in the nose intakes, passing under the cab
floor to the engine room. There, a set of four fans forced the air into the
engine compartment, but the radiators themselves were nothing more than finned
pipes flanking the engine against the ceiling with the air being allowed to
travel out of the carbody through openings flanking the manifold and in the
floor. Later, some units received additional vents, sometimes on the roof, or
by the conversion of existing windows. UP was also unhappy with the rate of
cooling for the traction motors, and this is the reason for the retrofitted
slots in many of the City unit pilots. Later, UP would order slotted (so-called
"Challenger") pilots, like on the pre-war slant-noses.
>> Now Q-related stuff: How were the diesel motors in
the shovel-nose Zephyrs cooled? I don't recall seeing any radiators or grilles
on them. <<
It's as plain as the nose on your face (or the grills flanking your headlight
<tehee>) - Those grills above the shovel-nose windshields were real, and at the
rear bulkhead above the cab ceiling (the point where the roof section becomes
constant) there were two fans to force the air further into the engine room.
Radiators again flanked the engine near the roof, and air exhausted from the
engine room both upward and downward. On the early articulated trains, the
exhaust capacity was soon augmented by eight saw-tooth vents, four on each
side, flanking the manifold "bath tub". On the EA models (9904-9907), the
intake and radiator installations were similar, but generous roof vents were
provided at the rear ends of the units. The B-units (9906-07B) had additional
vent space at the rear, since they lacked the front grill for intake, and these
openings apparently served both for intake and venting, since the fans were
mounted backward, at the rear of the engine. (the arrangement on the EAs would
cause serious problems when they were converted for use as pool boosters at the
end of the '40s. Cooling was fairly good if the unit were lashed facing
forward, but if the former shovel-nose trailed, they would sometimes overheat -
because suction through the now-rear grill space was fighting the fan-driven
airflow inside the car body. Late photos of these booster-As show some peculiar
arrangements of air foils around the grill area, as though the engineers were
trying to correct the airflow. In retrospect, the problem *might* have been
solved had they used reversible fan motors so they could (quite literally) "go
with the flow".
9908, last of the shovel-noses, seems to have finally solved most of the
cooling problems. As "half-an-E-5", 9908 benefitted not only from a carbody
side vent (located above the pier panel and covered in a fabricated grate) and
early E-3-style roof louvers, but had the additional air forced from the
over-windshield grills (which were noticeably smaller than earlier versions).
>> One final item: I am assuming that the grilles on the
E- and F-units covered radiators used for cooling the
diesel motors inside the units. <<
Not exactly - The radiators were mounted similarly to what I described above,
and the air vented (or later was fan-expelled) through the roof. All side
openings were intakes to the carbody, and - as a photo-history of almost any
EMD cab unit will show you, weren't enough. Throughout the history of carbody
diesels, EMD kept adding intake space to the sides, and railroads kept
retrofitting additional openings.
>> Were these car-type radiators or something else? <<
Similar, but much heavier-duty.
>> Also, how effecient were they? Did they actually get the job done? <<
As indicated above, the radiators were fine - quantity of airflow was the
problem.
Marshall Thayer
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