Correct the Firefly VC's speed

[TDeacon]

Correct the AH game speed for the Sherman Firefly VC from 20 mph to 22 mph.

Justification:   All references I’ve seen, including the 2001 Hayward “Sherman Firefly” book, give the Firefly VC a max road speed of 22.25 mph, and all other AH GVs appear to use their max road speeds for cross country travel (presumably for game play purposes). 

Note that the Hayward book also refers to a “sustained speed” of 20 mph.  However when you design speeds into a game (any game), you want to use the same speed definition for each platform.  “Sustained speed” (whatever that means) data is not used for the other GVs in AH.  If you use this type of speed definition for only the Firefly, you distort the relative performance between the Firefly and all the other GVs.  It’s like designing a set of naval rules and using trial speeds for Italian warships and design speeds (generally slower than trial speeds) for everyone else.  Not logical.  If we allow relatively mechanically unreliable German tanks like Panthers to tool around at maximum road speed, we should allow the much more reliable Sherman to do so as well. 

MH

[715]

You sure the maximum speed is used for other AH tanks?  The only two references I have for the T34/85 show a speed of 34 mph ("The T34 Russian Battle Tank" by Huges and Mann) or 33 mph (Wikipedia) while the maximum speed for the T34/85 in AH is 32 mph.

[HawkerMKII]

http://www.militaryfactory.com/armor/detail.asp?armor_id=248

http://www.militaryfactory.com/armor/detail.asp?armor_id=63

[Chalenge]

I believe the issues is that there are two different Firefly tanks. The AH Firefly is based on the M4 Composite chassis, or at least appears to be. This would be a possibility, since the British did modify at least a few of that model. That means it has the Continental R975 engine (radial) versus the Chrysler A57 5x6cyl (inline). If you look at the model closely you can verify this.

The 22.25 mph figure would be for the M4A4, which we do not have as an M4 let alone as a Firefly.

[715]

http://www.militaryfactory.com/armor/detail.asp?armor_id=63

That link shows the problem with knowing what's real: it doesn't even agree with itself regarding the T34/85 top speed.  The text says 34 mph the table says 30 mph.  I don't envy HTC trying to decide on vehicle and plane performance specs.

[TDeacon]

I believe the issues is that there are two different Firefly tanks. The AH Firefly is based on the M4 Composite chassis, or at least appears to be. This would be a possibility, since the British did modify at least a few of that model. That means it has the Continental R975 engine (radial) versus the Chrysler A57 5x6cyl (inline). If you look at the model closely you can verify this.

The 22.25 mph figure would be for the M4A4, which we do not have as an M4 let alone as a Firefly.

The AH hanger listing says "Firefly VC".  All the tank references in my home library give the 22.25 mph max road speed for that model. 

MH

[Butcher]

Wrong; where do you obtain your information?  I listed the Hayward book as one of my sources, which has footnotes and a bibliography.  

BTW, the hanger listing says "Firefly VC".  

MH

There were two different engines in the Firefly so he is correct, there is a reason the british tanks are slower - if your book does not show both engines or top speeds then it is probably a generic listing on the tank. One engine was a contiental Radial engine the other a Crysler inline engine.
I do know the British Firefly was 20mph and American engine fireflies were 22.25mph.

No Firefly did 25mph, however there were only a few Contiental engines used, the standard Firefly would be 22.25mph and that is what we should have in game.

[TDeacon]

There were two different engines in the Firefly so he is correct, there is a reason the british tanks are slower - if your book does not show both engines or top speeds then it is probably a generic listing on the tank. One engine was a contiental Radial engine the other a Crysler inline engine.
I do know the British Firefly was 20mph and American engine fireflies were 22.25mph.

No Firefly did 25mph.

He is wrong because we are talking about the Firefly VC, which is what we have in AH right now.  

I didn't say anything about 25mph, so what's with the red herring?  I *am* saying that all sources I have access to, including the Hayward book which is the most detailed book I know of on the Firefly, show 22.25 mph for the VC.  My sources do also show different speeds for different models, but since that is not the topic of the OP, I am not bothering to quote them.  

What are your sources?  Please don't quote websites. 

MH

[Butcher]

Nobody says it did 25 mph.  I *am* saying that all sources I have access to, including the Hayward book which is the most detailed book I know of on the Firefly, show 22.25 mph for the VC.  What are your sources?

MH

Hawker posted two links that show it does 25, this never happened.

I have the Hayward book too, it doesn't even mention both engines if i'm correct. Osprey Sherman Firefly, Sherman Firefly vs Tiger normandy 1944, Memoirs of Wilfred Harris, Hayward, Armor in action Firefly VC.

Are you insulting me by saying dont quote websites?

[Chalenge]

Looking at the model of the Firefly in game we do indeed have the VC (Sherman V), instead of the IC (Sherman I). Looking at the performance of the tank, it acts like a IC I would guess.

[Chalenge]

These are both Sherman VC Fireflys (fireflies?). 

Can you see why one might be faster than the other?

[TDeacon]

Hawker posted two links that show it does 25, this never happened.

I have the Hayward book too, it doesn't even mention both engines if i'm correct. Osprey Sherman Firefly, Sherman Firefly vs Tiger normandy 1944, Memoirs of Wilfred Harris, Hayward, Armor in action Firefly VC.

Are you insulting me by saying dont quote websites?

Butcher, no insult intended, but you did post a BBC website link as a reference when we discussed this same issue in the M36 thread.  

With respect to book references, yes the 2001 Hayward book does mention the power plants.  Among other places, there is a summary data table on page 177.  Of the books you quote, I only have immediate access to the Osprey “Sherman Firefly vs Tiger”.  I don’t see that it supports your claim that max road speed was 20mph.  Note that the author quotes Hayward as a source in his bibliography.  

Previously you posted:

There were two different engines in the Firefly so he is correct, there is a reason the british tanks are slower - if your book does not show both engines or top speeds then it is probably a generic listing on the tank. One engine was a contiental Radial engine the other a Crysler inline engine.

I do know the British Firefly was 20mph and American engine fireflies were 22.25mph.

I’m sure you know that British Shermans were made in the USA, and all used “American engines”.  The VC was their name for the M4A4 and used the Chrysler multibank engine.  The IC was their name for the M4 and used the Continental radial engine.  I would be interested in any source you have which indicates that the maximum road speed for the VC (M4A4) was 20mph.  A page number would be helpful.  

MH

[TDeacon]

These are both Sherman VC Fireflys (fireflies?).  

Can you see why one might be faster than the other?

<snip images>

Chalenge, the first is not an original Firefly; note the hull machine gun.  On a Firefly, this space was used for ammo storage, at the cost of one of the 5 original Sherman crew members.  The Hayward book calls these types of tanks "post war museum pieces", cobbled together out of spare parts probably by the museum.  

MH

[Chalenge]

Well, perhaps Hayward does say that. The tank is an M4A4 Sherman VC that has not fully been upgraded to British standards, at least. But, that's not the point of the images. The problem for the VC overall is weight, but also the trial specifications resulted in a road speed of 22.25 mph with the rubber block tracks. I first thought that a change to combat steel might make the difference, but now I think it has to do with changes made to the traverse gear by the Department of Tank Design after there were numerous failures in the field.

[TDeacon]

Well, perhaps Hayward does say that. The tank is an M4A4 Sherman VC that has not fully been upgraded to British standards, at least. But, that's not the point of the images. The problem for the VC overall is weight, but also the trial specifications resulted in a road speed of 22.25 mph with the rubber block tracks. I first thought that a change to combat steel might make the difference, but now I think it has to do with changes made to the traverse gear by the Department of Tank Design after there were numerous failures in the field.

You are probably mistaken on that tank ID.  The Firefly mods were made in the UK, and they wouldn't have added the gun without the other stuff.

But, to your main point, the Firefly VC (17pdr) is listed as being 3 tons heavier than a regular VC (75mm) tank.  That's why its speed was 22.25 mph versus the 25.2 mph of the regular VC (per Hayward, page 177, who claims his data came from original documents from the Bovington Tank Museum and the UK PRO).  

MH