Author Topic: AH Jugs, a couple questions (Read 664 times)

Vortex · « **on:** January 21, 2002, 12:28:00 PM »

I was wondering if anyone had any info to counter the following. It was my understanding that the 5" zero rail rocket stubs did not become a feature until the D40 version, not the D30 as AH has it. Prior variants to the D40 all used the standard bazooka tube 4.5" rockets as we see on the D25. Looking at the aircraft itself the D30 we have actually seems to be a D40. It looks to have the K14 gunsight (new feature on the D40's) along with the rocket stubs...heh, no tail warning radar though unfortunately

. Its just picking nits, but our D30 does seem to be a D40 for all intents and purposes. I'm curious if anyone has any documentation that suggests otherwise?

Also, anyone have an idea what props our Jugs use? Graphically they all look to be the same and probably best resemble the Hamilton Hydromatic common of all Evansville built planes (pre-D28 anyway when the Paddleblade became standard). That's not a good indicator though, I know. The performance charts would seem to indicate that the D30 has Curtis Paddleblade, what with its enhanced climb performance. So I'm guessing the D11 and D25 are modelled with the Hamilton's then?

Vortex

Vector · « **Reply #1 on:** January 22, 2002, 10:08:24 AM »

Hi Vortex!

This is punt for daff sancho ammo and other jug freaks who has some books

As far as I know, only D-30 has paddle blade prop, however IIRC D-11's (and later models) were equipped with it afterwards?

Daff · « **Reply #2 on:** January 22, 2002, 11:26:34 AM »

Paddle bladed props (of various types) were factory fitted from the D-21 (or 22, can't remember) onwards..however...all the 56th's P-47s (can't speak for other FGs), prior to that, were refitted with paddle bladed props. (Robert Johnson describes it in his book, btw).. I can't remember the date at all, but something like late '43, early 44?.

Daff

Vector · « **Reply #3 on:** January 22, 2002, 12:27:09 PM »

Hi Daff

Any mentioning about its effect to climb rate / speed vrs standard prop?

Vortex · « **Reply #4 on:** January 22, 2002, 01:04:38 PM »

According to the info I've got handy here Vector ("P-47 Thunderbolt in action," Squadron/Signal Publications) initially the props used were the Curtis 12'2" props. For a period later on though that changed and was determined by where the Jug was built. At about the time the D's started production a second factory for Jugs was started in Evansville. ,The main Republic plant in Farmingdale just couldn't keep up. Initially the aircraft were identical from the two plants with the only difference being their designation (RE for Farmingdale and RA for Evansville built planes).

With the advent of the D-22 things changed a bit. Up to this point all Jugs had used the 12'2" Curtis electric prop (not the Paddle yet). The Farmingdale plant began using the new Hamilton Standard Hydramtic for all Jugs build there. Evansville switched to the 13' Curtis Electric Paddleblade (C542S) at this point as well creating a new designation of Jug, the D-23. It was identical to the RE built planes short of the different prop. (Ibid, pgs 16-17).

It wasn't until the D-28 that the prop was standardized on the Curtis Paddleblade. From that point forward both plants used only that propeller and the models became identical again regardless of where they were produced.

So based on that I'm guessing our D-11 data was with the original 12'2" Curtis prop. The D25 could be either the Hamilton or the Curtis depending upon where it was built. However the reduced climb numbers suggest it was a Farmingdale Jug using the Hamilton prop. That was one of the big advantages of the paddle as I understand it...better climb. The D30 (or D40 if the stuff in my first post is correct) should indeed be using the Curtic Paddle prop.

As you guys note though this is just factory data. Field modifications were indeed common and its anyone's guess what happened out there.

Vortex

Vector · « **Reply #5 on:** January 22, 2002, 01:14:56 PM »

Thx for the info! Very interesting reading. I'm planning to buy America's 100.000 do this "bible" contain this kind of accurate info of all US WWII fighters?
Thx!

Sancho · « **Reply #6 on:** January 22, 2002, 02:44:40 PM »

Prop: Pyro has stated that our -11 has the old toothpick style prop, not a paddleblade. The -25 and -30 do climb better than the -11, which can be explained by their increased power and the paddle prop. The -22 was the first jug to have the paddle prop from the factory, however as Daff noted, the 56th and other 8th AF units received paddle blade upgrades as early as late December '43. I think you're right in that all the 3d model props on all 3 jugs are the same toothpick design, but that's not something you notice once the prop is spinning at 2800 RPM.

Gunsights: I can't be 100% sure, but the AH -30 looks to have an N-3A gunsight. The -25 look like a Mk. VIII gunsight. I don't know what is on the -11, but I think it should be a Mk. VIII. Anybody know?

Rockets: 5-inch HVARs mounted on zero length launchers were used in combat prior to being installed as factory equipment on the -40. Bodie's book has several pictures of 9th AF jugs loaded for a mission with HVARs under the wing.

Some more nit picks: the -25 is actually a -27 if you look at the plane serial number on the tail.

Buzzbait · « **Reply #7 on:** January 22, 2002, 05:21:29 PM »

S!

All P-47`s in the European Theater were re-equipped with Paddle blade props in the first week of January 1944.

Hence Robert Johnson`s P-47D-5 got the paddle blade upgrade to go along with the water injection upgrade it got in the Fall of `43. The factory D-5 had neither.

Upgrading was a continuous ongoing process. It basically brought all the older models up to current power and equipment standards.

When the older model Razorbacks got the upgrades it actually put them ahead in terms of performance to the later model bubble canopy models. The later models were heavier as a result of having additional internal fuel tanks and strengthened bomb mounts under the wings and in the belly.

Hence Robert Johnson called his D-5 the best performing P-47 he ever flew.

A test in another post on this board showed top speed for a upgraded Razorback as 440mph, quite a bit faster than the 429mph the D25`s showed.

The climb rate would also be better than the bubble canopy models.

We need either to have the option of having the Paddle blade on the D11, or a new P-47D21 Razorback.

I think it is simpler to have the former.

As mentioned many times before, the top scoring USAAF Aces didn`t fly P-51`s. They flew Razorback Jugs and they got most of their kills during the period Jan. `44 to July `44 when the Razorback D was the primary Escort fighter, not later when the P-47 was assigned the ground pounding role.

Sancho · « **Reply #8 on:** January 22, 2002, 06:37:19 PM »

You can't totally appreciate the difference in performance between a jug with versus without paddleblade by looking at AH's 3 jugs. Yes, the -25 and -30 have paddleblade, but they are quite a bit heavier than the -11. So they climb a little better than the -11, but not really anything to get excited about: at sea level the -25 climbs only 100 FPM faster, and the -30 with it's increased horsepower climbs 300 FPM faster.

Now, if you threw a paddleblade on the current -11 and compared it with the -11 minus paddleblade, that's where it gets really interesting. Already the fastest jug in AH, the -11 would gain 10mph in top speed. It would have climb speed advantage of 600fpm at sea level. Time to 30,000 ft would decrease from 20min to 13min. That's an aircraft I would really like to fly in the MA--one that approaches the performance of Robert Johnson's "Lucky".

OTOH, there's a good argument for keeping it the way it is. The lack of paddleblade allows us to use the -11 as the representative 1943 jug for scenarios. It can double for P-47Cs on up. Throw the paddleblade on, and increased performance shoots it into 1944 where it would have unfair advantage.

This is one clear candidate for a "perk loadout" if HTC ever decides to implement such a system.

vector at work · « **Reply #9 on:** January 23, 2002, 12:52:47 AM »

Quote

Originally posted by Sancho
Already the fastest jug in AH, the -11 would gain 10mph in top speed. It would have climb speed advantage of 600fpm at sea level. Time to 30,000 ft would decrease from 20min to 13min. That's an aircraft I would really like to fly in the MA--one that approaches the performance of Robert Johnson's "Lucky".

OTOH, there's a good argument for keeping it the way it is. The lack of paddleblade allows us to use the -11 as the representative 1943 jug for scenarios. It can double for P-47Cs on up. Throw the paddleblade on, and increased performance shoots it into 1944 where it would have unfair advantage.

This is one clear candidate for a "perk loadout" if HTC ever decides to implement such a system.

S!

Increase in performance would be significant! I agree we should keep D-11 as it is, but could there be any way to add paddle blade prop for D-11 as an perk-option to choose from hangar? 5 perks? This shouldn't be too hard to do by HTC, right? Another way could be make D-22 (or something). No need to do much graphics changes either, just replace 56th FG colors/markings with 348th FG's

Adding paddle blade prop to D-11 wouldn't make it any uber plane that's for sure, but it could see more action in MA thought. There are many dedicated jug nuts that prefers razorbacks over the other models and this would be a dream come true!
HTC please make paddle blade for D-11 or make D-22 and we promise to stop whining about P-47N (for a week or two).

Daff · « **Reply #10 on:** January 23, 2002, 07:48:43 AM »

" at sea level the -25 climbs only 100 FPM faster, and the -30 with it's increased horsepower climbs 300 FPM faster. "

Hmm that doesnt sound right..I dont have my books here at work, but the difference should be bigger.

" That's an aircraft I would really like to fly in the MA--one that approaches the performance of Robert Johnson's "Lucky"."

Well..except "Lucky" had max MAP increased to 72" and could do around 470mph TAS@30k

.

Daff

Vortex · « **Reply #11 on:** January 23, 2002, 10:55:51 AM »

Ok, that's starting to make a bit more sense now. Thanks folks.

The difference in wep based roc between the -25 and -30 was throwing me off too. I'd forgot that with the -27 came a hp boost when water injection was added for wep. That explains the identical non-emergency powered climbs but the better emergency roc for the -30.

I'd have to agree with the general sentiment here as well that finding some data charts on a paddle bladed razorback Jug would make for an excellent addition to AH.

Vortex

bozon · « **Reply #12 on:** January 23, 2002, 01:55:25 PM »

Quote

HTC please make paddle blade for D-11 or make D-22

oh yes, please !!!

Bozon

Daff · « **Reply #13 on:** January 23, 2002, 02:18:50 PM »

"I'd forgot that with the -27 came a hp boost when water injection was added for wep."

No, Water injection was added on the D-5 onwards. (Earlier C-models were prepared for it and were retro-fitted).
From the D-28 (27?) onwards, max MAP was increased to 68" from factory, giving a WEP-output of 2600HP instead of 2300HP.(But military power remained at 2000HP).

Daff

Buzzbait · « **Reply #14 on:** January 23, 2002, 08:27:42 PM »

S!

Actually if I remember correctly water injection came first installed in Factory on D11. That is why HTC selected it, as they like to base things on Factory specs.

That is why we will likely get D-21 as the paddle blade version if we ever get one.

Unfortunately the D21 may weigh more than the early Razorbacks. Not sure since I don`t have figures on the earlier `D`s.