Author Topic: Twin TP400 Hercules  (Read 775 times)

Offline apophenia

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Twin TP400 Hercules
« on: May 19, 2019, 06:45:40 AM »
This notion sprang out of M.A.D's concept for overwing nacelles on the Hercules. I've since had second (third?) thoughts about those overwing nacelles. Mostly it came from looking at other re-engining jobs on turboprop transports. It seems to me that - in constrast with Antonov's An-32 - the commonest solution to big increases in shaft horsepower is props with more blades. [1]

One example is the Aeritalia G.222L with (albeit derated) Tynes in place of T64s. Going from 3-bladed HamStans to 4-bladed BAe propellers was all that was needed. (Although, I must admit I love the idea of full-powered Tynes mounted over the wings of a stretched G.222!)

With the Herc itself, multi-blade props handle the C-130's more powerful AE 2100s. And, at the more extreme end, Marshall's 'Snoopy' testbed could mount a huge Europrop TP400 amongst its T56s thanks to the former's 8-bladed sickle props. Below is a retouch of 'Snoopy' showing the revised TP400 nacelle duplicated (with the outboard nacelles removed) to show what I mean.

From that, I conclude that the obvious approach to a TP400-Hercules would be a twin-engined 'Giant Spartan' >;

Two TP400-D6s would give this re-engined Herc a total power of 22,000 hp (versus 18,550 for the C-130J's four AE 2100s). A downside is a slight weight increase - 8,333 lbs total dry engine weight for the two TP400s vs. 6,910 lbs for four AE 2100s (or 7,760 lbs for four T56s). On the other hand, with the TP400-Herc, all that iron mongery is being carried closer in. Dunno if that's much of an advantage.

Anyway, the big selling point for such a conversion would be engine commonality for A400M users who also operate Hercules. Stealing a suggestion by Logan, such re-engining would make most sense when combined with a wing box replacement programme. New engine bearer points and wing strengthening could all be incorporated into new centre sections.
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[1] Other than re-using existing nacelles, this approach has obvious advantages for maintenance. Engine changes are greatly simplifed compared with the Clank. Even performing simple mtx on An-32 engines can't be for techs with any fear of heights!
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Offline Logan Hartke

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Re: Twin TP400 Hercules
« Reply #1 on: May 19, 2019, 08:30:07 AM »
Looks great, apophenia!

Offline Brian da Basher

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Re: Twin TP400 Hercules
« Reply #2 on: May 19, 2019, 07:54:57 PM »
Looks great, apophenia!

Concur. If you slipped that profile into a reference book, I bet no one would guess it wasn't "real".

Well done, apophenia!
 8)
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Offline kitnut617

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Re: Twin TP400 Hercules
« Reply #3 on: May 19, 2019, 10:19:45 PM »
C-130/A400 comparison. Looking at my model of the A400/A310, the engines look about like that on the A400 Steven ---
« Last Edit: May 19, 2019, 10:25:00 PM by kitnut617 »

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Re: Twin TP400 Hercules
« Reply #4 on: May 20, 2019, 02:07:02 AM »
Nice to see this idea start to get more traction since we first discussed it ~8yrs ago. :-\  http://beyondthesprues.com/Forum/index.php?topic=74.0
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Offline kitnut617

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Re: Twin TP400 Hercules
« Reply #5 on: May 21, 2019, 11:11:46 PM »
Couple of pics of a C-130 fuselage with A400 wing on top. The pics might show it (and maybe not), but as is, the prop tips of the 'inner' engines are lower than the bottom of the fuselage. Of course the C-130 wing doesn't droop like the A400 wing does but then the A400 wing is mounted above the C-130 wing box.  The A400 nacelles are massive, third pic shows one beside an Bell 412.
« Last Edit: May 22, 2019, 06:22:30 AM by kitnut617 »

Offline kitnut617

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Re: Twin TP400 Hercules
« Reply #6 on: May 21, 2019, 11:25:51 PM »
The A400 is as big as a Short Belfast ---- now a TP-400 powered Belfast might be something ---

Online elmayerle

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Re: Twin TP400 Hercules
« Reply #7 on: May 22, 2019, 12:03:35 AM »
The A400 is as big as a Short Belfast ---- now a TP-400 powered Belfast might be something ---
Hmm, sounds like an interesting 1/144 project.

Offline kitnut617

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Re: Twin TP400 Hercules
« Reply #8 on: May 22, 2019, 12:05:59 AM »
Something to keep in mind here, the diameter of a C-130 fuselage is 14 feet. The TP400 props have a diameter of 17 feet.

Offline kitnut617

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Re: Twin TP400 Hercules
« Reply #9 on: May 22, 2019, 12:06:46 AM »
The A400 is as big as a Short Belfast ---- now a TP-400 powered Belfast might be something ---
Hmm, sounds like an interesting 1/144 project.

Or even a C-133 Evan

Online elmayerle

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Re: Twin TP400 Hercules
« Reply #10 on: May 22, 2019, 12:20:37 AM »
Need a new wing for the C-133, ISTR that the wing was one of the low-life components of that aircraft, even with the engines it had, let alone with the rather more powerful TP400's.

Offline apophenia

  • Patterns? What patterns?
Re: Twin TP400 Hercules
« Reply #11 on: May 22, 2019, 05:10:24 AM »
Thanks folks.

kitnut617: Thanks for the comparison shots!

The A400 is as big as a Short Belfast ---- now a TP-400 powered Belfast might be something ---

Mindful of Greg's 8-years-and-counting note, has anyone ever suggested a twin Tyne RAF Hercules?

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Offline kitnut617

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Re: Twin TP400 Hercules
« Reply #12 on: May 22, 2019, 06:33:56 AM »
However, having shown all that, there was this C-130   :-[
« Last Edit: May 22, 2019, 06:40:44 AM by kitnut617 »

Offline apophenia

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Re: Twin TP400 Hercules
« Reply #13 on: May 22, 2019, 07:24:36 AM »
However, having shown all that, there was this C-130   :-[

Yup, that's Snoopy in its final role  :smiley:
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Offline kitnut617

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Re: Twin TP400 Hercules
« Reply #14 on: May 22, 2019, 08:36:53 AM »
After I had posted my pics of the kits, I had suddenly remembered I had seen an article about the C-130 FTB. I seem to remember now that they had to move the outer engine too. It sort of looks like that's what they did in the second pic down.