In article ,
"Gord Beaman" ) writes:
(Peter Stickney) wrote:
Well, with a Lanc, if it wasn't a Merlin 24/224/225, it would have
been a Merlin XX or 22. The only differnece being that the Emergency
adn Takeoff ratings were a bit lower. (Takeoff 3000R/+12 for the
Merlin XX, 3000R/+14 for the 23, and Emergency ratings of 3000R/+14 in
Low Blower and 3000R/+16 in high) They still had the boost controls,
and, of course, the COnstant Speed props.

As for wher the storys come from, they pop up all the time. Somebody
hears something that they think they understand, get it a bit wrong,
and as they repeat it, it grows.

Yes they do don't they?.

As to your power limits for the 224/225 some aspects don't look
as I remember them. (Now take note that this was nearly 50 years
ago so cut me some slack) I thought that the max RPM was 2900
(remember that I have some 16 years on R-3350's with 2900 RPM
limits so this might be the reason that I think that). Also I
know that the max boost was 18 in low blower. I don't remember
what the boost limits were in high blower but it seems odd that
they'd be _higher_ than in low. So as not to mislead you about
those power limits I have two old F/E friends here in town who
flew Lancs so I asked both of them just now. One isn't sure of
the max RPM but 'thinks' that it's 2900 and the other is 'sure'
that it's 2900 and they both agree with me about the boost limits
which were 9 pounds (at the 'gate'), 14 pounds at full throttle
and with the 'boost over-ride' pulled (which cut out the
Automatic Boost Control - known as 'pulling the tit') gave ~18
pounds.

It seems that I wasn't explaining myself too well last night. (I _told_
the wife that all that yard work would screw up my brain)

You are, oc course, absolutely correct about the Merlin 24/224/225
power settings. In my own muddy way, I was referring to the engines
used in most of the earlier wartime RAF Lancs, which were, of course,
the earlier models, which weren't rated at such high boosts.
According to my Lanc III Pilot's notes (I finally managed to get a
copy, Hooray!), your quorum of FEs is quite correct aabout the gate
settings.

The whole question of power settings on Brit engines puzzles me
somewhat, to tell you the truth. To take an example, I've been
working on some engineering analysis of the Mosquito, so I've got a
pretty good handle on what the engine performance and airplane
performance numbers are. The only catch is, most of the published
airplane performance numbers don't bear any relationship to what I've
calculated from the info I have. The published numbers for the 20
series Merlins give, if you're lucky enough to find something other
than takeoff power, the Max Power, which I've described above, The
Climb Power, which was 2850R/+9 boost, and Max Continuous, which is
2650R/+7. That's all well & good, and normally things can be doped
out from this by applying a bit of science. But it appears that the
actual trials were flown at the 3000R/+9 gate, which is throwing
everything off. I'm not really complaining, mind you. It's turning
out to be an interesting study, and should be the basis for an
advisory article for other researchers about the importance of knowing
the context of what's being tossed around.

AS for why the earlier 2-Speed single-stage Merlins had that
asymmetrical power setting, with reference to Low & High blower Max
Power, what I can figure is that it's due to the lower ambient air
temperature at altitude allowing more compression without raising the
non-intercooled carburetor inlet temperature beyond some threshold.
The engine was certainly capable of producing more - the differences
between a Merlin 22 and 24 are more small details and calibration than
anything else.

I realize that you're a damned fine researcher and have a lot of
facts at hand and I feel a little timid about 'instructing' you
but I'm very sure of my facts about these a/c. I logged 575 hours
as F/E on them.

Gord, please do not _ever_ feel shy about correcting or instructing
me! I'm not going to learn, otherwise. Barring an unbelievable
piece of fortune, you've been able to Be There and Do things that I
can only read about. I'd like to think I outgrew the Know-it-all Snot
stage about 20 years ago. My research, and the stuff that depends
from it, can let me tell what, and how, and, at least in the case of
the machines, why, but it can't ever take the place of the people who
actually were in the hot seat. Research all I might, it's no
substitute for experience. Despite the advancing years, and the
thinning numbers, there's still an incredible group of people with
real experience that spans more than 60 years, all on tap. Not cold,
impersonal mathematics, or stories passed from hand to hand so much
that all the edges are worn smooth, but people who were really there,
and made it through. (I was going to make a list of the folks here
who's opinions and experiences I value, but it started running too
long, and I was afraid that I'd leave somebody out, (which would be
unfair), so I won't name names.)

Let's just say that if I'm talking through my hat, please do call ne
on it.

They were Lancaster X (MR) with Merlin 224/225 engines as used by
the RCAF in Canada for ASW work in the early to mid fifties and
replaced in (I think '55) with Neptune P2V-7's (with no jets
installed until later).

You mentioned that you were going to be attending a gathering of your
RCAF/CanForce fellows this fall. I've managed to dig up a beautiful
color photo of an RCAF Argus and a USN Neptune formating on each other
during the Cuban Missile Crisis. I can swing acanning it, and
shooting off a large-scale (B or C size) print of it, if you'd like.
Oh, yeah - on the Pinetree Line website there's a rather good quality
color image of an ASW Lancaster that suffered a maingear collapse at
Stephenville/ Ernest Harmon AB, in the mid '50s. While it's not the
most dignifies shot, it's a good study of a workhorse late in its
life. Like every other Canadian Military airplane I've seen, it
looked to be in remarkable shape - did you guys have people specially
detailed to polish 'em?

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster