Category Archives: Firecontrol

Post #70: Report on the New Weapons Board

Post #70: Report on the New Weapons Board

I downloaded this PDF, Report on The New Weapons Board 1944,  someplace, but since I don’t remember where I hosted it too.  The report documents the feedback the troops gave to the board on the various weapons they demonstrated.

The report was put together in early 44 to document feedback from the troops on current weapons, and proposed improvements, and replacements. There is a good amount of information on the M4 medium tank, and US Armor in general. Most of the combat feedback comes from the fighting in Italy, and North Africa.

The report also sheds an interesting light, and gives evidence for the view that the US Army didn’t consider the improved early Sherman bad, and only wanted it replaced with something much better.  It also gives some interesting insight into the Shermans and what condition they were in when they got to the using units.

Feedback on current equipment and changes.

This is a typical M4 Sherman in Italy, the battalion is being used as an artillery battery, and this is an early production M4 with the M34 gun mount and it probably has a three piece differential as well. It may even have DV ports. These tanks were common in the MTO even into 1944.

The first thing is this to note about the Sherman is the first mention of it is praise for the current models. This quote stands out, “No new type is desired unless the improvement in military characteristics is sufficient to warrant the changes and defects in the present standard tanks are avoided.” 

Another early model M4 in Italy, cheek armor, M34 gun mount and early 3 piece differential.

They did have a list of improvements they did want either done to the Sherman, and to make sure the follow on model, the T20 series incorporated them. 

  1. They wanted a 76mm gun like the 3-inch gun on the M10.  The news of the 76mm M1 series and the new Shermans mounting the gun interested the troops a lot. They brought an M4E6 76mm Sherman.
  2. Improved suspension and tracks. It turns out the rubber block tracks with no chevron were not well liked, and wore out very quick in rock, hilly terrain. The steel chevron blocks with rubber backs were well like and lasted much longer. This feedback is mostly from the ETA, the mountainous and rocky landscape was hard on tanks and even the Sherman had some issues. The complaints about the suspension had more to do with width than durability.
  3.   They wanted armored air cleaners on the M4 and M4A1 tanks.  It turns out the Air cleaners mounted under the overhang on the rear hull of the M4 and M4A1 tanks were prone to damage, and this damage was not expected, and didn’t pick up until Italy so there was a shortage. All other models  had the air cleaners inside the hull. Some units added improvised armor and some was added later in the production runs.
  4. Better ballistic angle around the front of the transmission housing.  The old three part differential is what they are talking about. Most early shermans had this type, and the armor was thinner than the later cast single piece units. There were two cast versions, an early thinner, but still no worse than the three piece unit, and a later improved thicker one. There was a demand for add on armor over this area, but it was never approved.
  5.  More power. Yet, when the M4A3 Ford GAA powered Shermans came online, they did not want to swap them in as replacements, and only wanted whole units who trained on them stateside first to be issued the improved tanks.  The M4A4 and M4A2 were not big enough improvements to switch to those motors. 
  6. Diesel engine. The US Army rejected the GM 6046, claiming it was not as reliable as the R975, but all the nations that did use this motor liked it.
  7.  They wanted better sights and fire control equipment. Many tanks in the MTO and NATO(North African Theater of Operation) had not gotten the M34A1 gun mounts with telescopic sights. The mount for the periscope sight had not seen major improvements, though there were field mods to make it work. The using arm was enthusiastic about the changes in the second gen Shermans fire control, but wanted even more advanced features, like range finders, and improved telescopes, since the current ones shot loose to!

There is also other tank related info.

  • The M3 75mm Gun –  Though well liked for infantry support and deemed to be reliable and durable, the using arms almost universally felt the German 75mm PAK 40 guns were much better anti tank weapons, and a high velocity 76mm gun was in demand.
  • 75mm ammunition – these fixed rounds came unfixed, sometimes even in their travel packaging.  They wanted this fixed. They wanted the WP shells ballistics to match the ballistics of the common HE shell.
  • Large caliber cartridge cases – Steel cases for the 75mm rounds for the M3 gun were well received and proved more durable.  This was not the case for 105mm howitzer rounds.
  • 105mm howitzer armed tanks – This was not a popular notion because the M7 105mm GMC was inaccurate in direct fire when used close assault.  The new weapons board did not agree, and plans for this vehicle were already in motion, and it would be well liked once issued.
  • Tank Officers – they wanted a tanker in the high level headquarters to advise Division and higher level officers the best way to use tanks. AA and Tank destroyer officers were already an accepted part of these HQ staffs.
  • the 17-pdr gun – There was more interest in using this gun in M10s, since the install was much simpler, the Sherman install was complicated, and cramped and the Army was leary.
  • Tank Tracks – They show up again and the plain rubber block tracks could wear out in 250 miles in rock terrain, and lacked good off road traction, and the using arm felt they were only good for training on roads.  The T54E1 steel chevron type was preferred and much more durable, but the T48 rubber chevron would work in the MTO but wore out faster than steel types. The T49 bar cleat was also not good on sidehill terrain. The using arm wanted a wider center guided track in the MTO because the side guided tracks on the Sherman were prone to throwing on irregular and rocky side slopes. Extended end connectors were well received by the using arms.
  • Tank Suspension – Sherman suspension was found to be durable, with few volute springs failing. The biggest problem was the bogie wheels, since the rubber tires had an erratic failure rate, and unlike the spring failures, usually sidelined the tank.
  • Ammunition stowage – They using arms were not interested in changes that reduced the number of ready rounds. The turret ready racks were very popular and crews did not like their removal with the ‘quick fix’ mods. They were willing to risk the higher fire chance, for the faster rate of fire the early storage setup allowed. The crews did not get their way on this one, at least until the M26 went into production.
  • The Radios – They wanted a better radio in the M32 recovery vehicles and better, more comfortable headphones for the armor crews.
  • The M10 GMC – This TD was very popular, and received high praise all around. There usering arm did not require a replacement, just improved M10s. ♠ One thing to note, most M10 GMCs in MTO lacked the Azimuth indicator and range quadrant. Since the M10s get used as artillery a lot in the MTO, they would like replacements to have them.

    M10 in Italy.
  • Replacement gun tubes – The using arms were very annoyed, that all type of gun barrels from machine gun and mortar, to tank and artillery were dispensed at a very miserly rate.  The using arm argued replacement barrels should be bought at the rate that took into consideration how much ammunition for the same weapon was produced.
  • Improved fire control for all relevant vehicles –  They wanted built in range finders, or portable ones supplied. Better periscope and telescope sights and all vehicles that could be used for indirect fire to receive the full suite of tools to perform the task.  Up to reading this, I had never heard that some Shermans did not get these automatically. I’m not sure why some Shermans and TDs didn’t have the Azimuth indicator M19 and elevation quadrant M9. Maybe the crews dumped them to save space, maybe the tanks were rushed and built and approved without them I’ll try and find out. T hey mention 75% of the tanks in England had these items, but less 50% had them in the MTO.  Tank units were much more commonly used for indirect fire in the MTO than they would be in the ETO.
  • Engines –  The R975C-1 was getting around 200 hours before needing replacement. This was fine with the using arm, though they would like 60 to 100 more horsepower.  The R975 needed little maintenance to reach the expected 200 hours and many run much longer.  The lack of liquid cooling system has some advantages.
  • Powertrain –  There was a higher than expected rate of clutch failure in the desert campaigns. The clutch system was also improved on the production like with improved leverage to lower the clutch pedal pressure. Many MTO units did not receive the improved clutches or linkages.  The better clutches lead to better transmission life and better shifting, and even without the improved clutches, transmission life went up in Italy.  The powertrain offered excellent service and generally outlived the engines by several overhauls if not damaged.
  • Crew comfort – the Driver and Co-drivers seats in the Sherman were found to be ok, but higher seat backs were requested along with deeper seat cushions. The Gunners seat was found to be ok, but could use the same improvements as the drivers seats but the Command and Loaders seats were deemed all but useless. These would be improved in the later models of the Sherman and various TDs.  Crews do not use their seatbelts, fearing it complicating bailing out, and more padding inside was not wanted because the crews felt it was a fire hazard.  The M4 and M4A1 tanks were praised for good ventilation. There was also some discussion about the value of turret baskets, and if they were needed at all.
  • Ammo Storage – The early Sherman ready racks in the turret were well liked by the using arms, but they felt the sponson and hull ammo racks were no good and didn’t support the 75mm Shells enough. They would often separate and dump a bunch of gun powder inside the tank making a deadly mess to clean.  The using arm tends to stuff the tank with extra rounds, adding to the shell durability problems. These problems would be addressed in the second gen improved hull tanks.
  • General storage – The current storage space on the Sherman was deemed ok, but better, easier to access bins were requested. They also wanted any storage in the floor to be resistant to getting filled with dirt or water.
  • Machine guns – The bow machine gun see a lot of use, but it’s usefulness would be improved by a sighting system. One was in the works, but not at the point of this report.  The M1919 machine guns, both bow and co-ax were reliable as long as the crew was careful with the ammo. Long road trips could vibrate rounds loose in the belts and cause problems, but under normal conditions this was rarely a problem with well trained crews.  The crews wanted a better adjustment method for matching the co-ax gun to the gunners site, the current one was not very good.  The .50 AA mount was not well liked or considered important. Requests were made for better mount for ground targets.
  • Turret hatches – The current split hatch was deemed ok, but the crews like the looks of the new all around cupola, and were also enthusiastic about a loader’s hatch on the new 76 armed tanks.
  • Armor – There does not seem to be a consensus on how much armor a tank should have by the using arms.  Armored Force troops felt the current level on the Sherman was fine, but wouldn’t mind more as long as it did not negatively affect flotation, maneuverability, and speed. ♠The British generally wanted heavier armor than the US Army.    ♠♠Combat in Italy showed the differential was taking more hits than anything, and another request was made for add-on armor for the area.
  • Sand Shields – The general consensus on these was they were useless in any theatre and needed to be redesigned. They needed to be easier to install, and designed to not trap mud.
  • Flotation – The using arms wanting tanks around 10 pounds per square inch. This was very optimistic, since even the HVSS Shermans came in around 11 PSI, the basic 75 vvss Sherman around 13.  It seems the Germans flooded fields in Sicily and Italy and they retreated, and Shermans got bogged down most of the time.  They offered the suggestion of just stretching the Sherman, since more length would help, and the British M4A4 tanks, the longest production Shermans had no maneuverability issues.
  • Maneuverability –   In the US Army there was a desire across the board for more maneuverability, in tanks. One thing to keep in mind though is the tanks in the MTO were older and most had single anchor steering brakes, the double anchor made the tanks easier to maneuver requiring less lever pressure. The ability to skid turn was not something US troops seemed interested in.
  • Accessories – The troops had a lot of feedback here. ♠ The instruments and gauges in medium tanks were not good quality, if they worked they didn’t work long. Oil pressure gauges fail, and no one worries about the motor until both oil pressure gauges die and a low oil pressure light comes on. This seems to be US feedback, I don’t recall hearing complaints from the Brits about Gauge quality. I wonder if the different tank plants sourced gauges from different companies. ♠♠ The compasses on US tanks would not stay calibrated. This would be a very anoying problem. ♠♠♠ Armor for the air cleaners on the M4 and M4A1 comes up again. ♠♠♠♠ The Auxiliary giving good service, and are well liked, but the using arms would like the area area the fuel tank filler for the Aux motor be waterproofed better.  They also noted replacements were hard to come by.
  • Modifications –  ♠ The jist on this one was, in many cases modifications can be seen by inspecting a vehicle, but in others, access panels or more might have to be removed to check. The using arms proposed a record imprinted a brass plate, attached to the vehicle, listing all the modifications that had been applied. ♠♠ They also wanted to emphasize that they did not want any modifications that would not ‘materially increase  the efficiency of the vehicles’
  • Development – The using  werte curious  about the items in development, and finding out a large organization was working to improve almost everything was a morale booster. There was also interest in the T-20 series and if any test vehicles would be sent over for some congress.

 

Information and feedback on future equipment. 

  • The M4E6 or pre production M4A1 76w –  ♠ This improved version was well liked by everyone who checked it out. The bigger turret was a big hit, though not much bigger, it seemed roomier. ♠♠ The improved fire control gear was very well liked and considered an ‘outstanding improvement’.  The 76mm gun was well liked, and every seemed to agree needed. ♠♠♠ The only real concern was the less effective HE round, but it was hoped they would make a better one.
  • The M18 76mm GMC –  The first and bad impression this vehicle lefts was it had no armor, and seemed very mechanically complicated.  The fire control gear was well liked. When the vehicle was demonstrated, the tracks and unthrowable tracks also got a lot of attention.  No one was sure if the speed would be useful, but the maneuverability was well liked. ♠ The  same story with interest in deployment, not as a replacement vehicle, but fulling trained units from the ZI would be ok. ♠♠ This vehicle was not wanted by M10 units already deployed. Units equipped with it in the ZI then deployed were better received, the M10 was still more popular.  An M10 with a 90mm gun was the prefered replacement.
  • M4A3 75W – Even though the Ford GAA was a big improvement, it was not enough of an improvement take them on as replacement vehicles. They were fine for them to be brought with units already fully trained on them.
  •  The M1 Dozer blade kit – This kit was an instant hit, and would have many uses, including clearing rubble after heavy artillery reduced a strong point.  Currently this has to be done by an un armored bulldozer and casualties were high.  it was hoped they would work well enough to help tanks dig in or SPG prepare a position.  ♠ Through testing, they found this kit  could be installed on any Sherman tank type.

This report goes into detail in the appendixes listing all the items demonstrated, and where they were demonstrated. They also include data on how many of the various items demonstrated were ordered by the various theatres.

I think it’s pretty clear the MTO was a backwater. The general shortage of spare parts in the MTO, and a shortage of personnel to staff the proper echelons of repair and salvage system are also indicators of this. As they got read for the June of 44 landings, the troops in England would be getting top priority and supplies and spares.

There is a lot of info on other weapons like artillery and small arms, not directly Sherman related and therefore, uncovered here. The report is definitely worth a download and re through.  I think it offers a good insight into the thinking involved on not swapping to 76mm armed Shermans before the Normandy landings.

Post # 68 The Chieftain’s Hatch does the M4A1, we review it.

Post # 68 The Chieftain’s Hatch does the M4A1, we review it: A great Hatch!

The video comes in two parts.

The subject of the video is  Black Magic, a small hatch, late production M4A1 if the turret came on it, though the turret or gun mount could be from other tanks. When it comes to restored Sherman tanks, I think being concerned about matching numbers is not a thing that seems to be worried about, and since it was so well designed and built, parts readily interchange. This sherman started life as a canadian Grizzly, basically totally the same as an M4A1 with an extra small hatch in the hull floor.

This tank has almost all the quick fix upgrades, the extra armor over the hull ammo boxes but lacks the cheek armor on the turret, and the turret may, I can’t tell for sure, have the cast in cheek armor, meaning it almost for sure didn’t come on the hull.  It also lacks the armor plates added in front of the driver and co drivers positions, that the Chieftain calls “sheet metal”.  It also has some late Sherman stuff, either added by the restorers, or by a depot rebuild later in the tanks life. The spot light, and ‘gun crutch’, or travel lock as normal people use were not on most small hatch shermans. Also the all around vision cupola would not be found on these tanks during WWII.

The Tom Jentz tangent. 

The Idea that the Sherman was no more reliable than any other tank, well, I don’t buy it. I like Mr Jentz’s work, and to some degree, his books helped inspire this site, since there was so little info on the web with really detailed info on the Sherman other than the Sherman Minutia site. I don’t think he really knows much about the Sherman if he thinks tanks like Panther and Tiger just needed more spare parts to be as reliable as the Sherman, it is a ridiculous idea. I do not think there was a single part on the Sherman that had a 500 kilometer life span, and that’s double the Panthers final drives.

First: The Chieftain himself has done Hatch posts on reports from the British, about how much more reliable, the M4A4 Sherman was than the Cromwell, even when both had full crews working to keep them running. both tanks were run thousands of miles, something late war German tanks could not do.

Second: In one of his own Hatches talks about the French experience with the mighty panther showed they averaged 150 kilometers per final drive set! Much less if the crew was hard on them.  There was no major automotive component including the oil, that had to be changed every 150 kilometers on any model of Sherman.

Third: This will focus on the Panther, since it was a major part of Germany’s late war armored force, and how terrible it was. This tank didn’t have just one flaw that should have disqualified it for production it had at least five. It was generally poorly reliable across all its automotive components, along with the final drive, 2500 kilometers for the motor and 1500 for the tranny were hugely optimistic and most of these tanks broke down and or were destroyed before they had to refuel. You had to take the whole drivers and co drivers compartment apart and the top of the hull off to change a transmission! Don’t get me started on the weak turret drive system that Rube Goldberg would have loved.  The  ‘wonderful’ dual torsion bar suspension and interleaved road wheels would cause any maintenance nazi to find the nearest US Line and surrender instead of working on it!

. . .

Another thing to note, you can see the holes drilled vertically in the suspension bogies, these are the tops of the holes the bolts that hold the suspension caps on go into. They were covered up with body filler by the factory, but on most restored and old Shermans the filler is gone, and they don’t fill the holes.

Note: the odd groove in the center of the rear Hull casting, this wasn’t done on all M4A1 tanks, and may have been unique to General Steel castings.

On the problems with the R975, I have not heard of complaints about the engine being easy to blow, and would be very surprised if the throttle wasn’t governed to prevent it.  On having to crank the engine before starting, I have it on good authority, that the crew could just start the tank and run it for a few minutes every 45 minutes to an hour to avoid having to hand crank the motor.

Many of units removed the sand shields in ETO to prevent problems with mud.

The Commanders vane site is an early version bolted to a late war vane site pad. The tank has the early style gunner’s periscope.  The gunners periscope is missing the linkage going down to the gun.  The radio looks like a 528.  Note the Armored doors on all the ammo boxes and ready rack. The tank is missing a lot of interior storage, it may have been removed in preparation on shipping the tank out to it’s new owners.

I‘m no expert, but I think the Chieftain confused a .30 cal ammo bin for the 75mm ammo bin right next to his shoulder for the location of an SCR-506, I just can’t see a WWII radio fitting in the tiny box! You can see how sparsely filled the interior is, as issued the tank would be stuffed full of items to help fight it, live with it, or keep it running.  The Chieftain shows just how easy even a small hatch Sherman was to get out of,  the the Loader was still going to have some issues though.  I wish he would have tried the belly hatch out, but maybe it’s welded shut or something.

He covers the small floor hatch on the Grizzly tanks, and you get a nice shot of the early escape hatch.  They also show the generator mounted on the rear of the transmission in one of the shots, briefly.  You can also see the full turret basket’s mesh screening that separated the turret crew from the hull crew. Part of the quick fix was to cut this all out.  I suspect most of the inconsistencies in the tanks details are due to the restoration crew using the Sherman parts they could get their hands on.  Very few people would  even notice or know it had the wrong commanders hatch, or even whole turret.

A note on the tank, it belonged to a the Military Vehicle Technology Foundation, a fancy name for the collection of a man named Jacques Littlefield. He had a passion for armored vehicles of all types but really liked tanks. He restored many to full functionality, including working main guns and machine guns on some tanks.  Owning a working tank cannon is easier than you would think, and far easier than getting the paperwork approved to own machine guns in California, and Jacques Littlefield did both.  He employed a restoration crew with world class skills and did some amazing restorations, including a Panther A that was impossibly damaged, but still brought back to life.  That Panther was his crowning achievement, and he was a real mover and shaker in the international military vehicle restoration scene, seeing that tank run was one of the last things he achieved, because cancer claimed him shortly after.

The MVTF was supposed to make sure the collection of vehicles, that were a labor of love his whole life, lived on when he passed. Unfortunately the location of the MVTF, Portola California, on a large chunk of very private property, with very limited parking really presented some problem.  The collection was used often while it was there, by TV productions like Myth Busters, and was a staple for the Wargaming Staff for their productions, and occasionally opened up to groups of vets, or other interested people.  There were other difficulties with the location, and ultimately the collection was donated to the Collings Foundation.  They reportedly decided to keep 40 of the most significant vehicles and auction the rest off.  The money from the auction was going to be used to build a facility in Stowe Massachusetts, but due to zoning issues, the permits were not provided, leaving the vehicles they did keep in limbo.

I‘m sure the Collings Foundation, a really amazing Charity, they keep many rare WWII aircraft, and cars, including race cars running, has a plan for the rest of the tanks. Their website only lists the Panther in their collection, I hope that doesn’t mean they sold the rest when the museum fell through.  That’s not a criticism of the CF, they I’m sure know their business far better than I do, and they really are a top notch group of people. Just browse that site to see the airplanes they’ve gotten flying.  The only real B-24 liberator and a working F-4 Phantom are just two of the notable planes!!  If you know anything about aviation, you know just how complicated and expensive keeping an aircraft like a Phantom flying is, especially if you don’t have the resources of the U.S. Navy or Air Force backing you.

I have to say, this is one of the best Chieftain’s hatches they have done. Granted, I’m a tad biased, since it was on the Sherman, well a Grizzly made into a later model small hatch Sherman anyway, and the Chieftain really has gotten pretty good with the Sherman and its sub variants, and even has a book on US WWII TDs on the way.

 

 

 

#64 Sherman Fire Control: How the Gun Was Aimed, not Putting Out Fires!

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Sherman Fire Control: How the Sherman aimed its Main Gun.

The Sherman tank went through a series of fire control changes each an improvement over the last.  The first tanks lacked telescopic sight mounted on the gun mount. The only site was incorporated into the gunner’s periscope, and it wasn’t magnified. Since the periscopes were all interchangeable, updating the older tanks was easy at least were the periscope was concerned.

The final fire control setup the Sherman gunner had at his disposal was pretty impressive by the standards of the time. He was in a hydroelectrically driven turret that rotated fast; he had very nice periscope setup with 1x and 6x scopes hooked into the gun with strong linkage.  He also had a telescopic sight to work with and the gun was stabilized.  This was a vast improvement over the unmagnified reticle on the first production models.

The Lee used a unique setup; the 75mm gun was aimed with an M1 periscope, with an M21A1 periscope built into it. The 37mm was aimed with an M2 periscope with an M19A1 periscope built in. Both the 37 and 75 mounts were stabilized. The prototype M6 Sherman used its own unique sight built into the sight rotor on the top of the turret, this was only used on a small number of production Shermans tanks.

Let’s look at the various periscopes and telescopes the Sherman used through its long life.  Let’s start with a look at the various versions of the periscope sights the production Sherman and the TDs based on the chassis below.

 

The M3 Periscope Sight

Since I just have a little info on this from TM 9-731B on the early M4A2, don’t have much to put here. Maybe this periscope is the one I’ve read about getting foggy on the inside in cold or humid locales. It was quickly replaced with the M4 detailed below.  This was one of the non-magnified periscopes.

m3-periscope-sight-for-use-on-early-shermans

The M4 Periscope sight

The Periscope M4; it had an M38 telescope with ballistic reticle inside, but no magnification. The M4 was not well liked, and the mount it fit in, was made from sheet metal and was a little flimsy.  The linkage that attacked it to the gun wasn’t very robust, and could be knocked out of alignment annoyingly easily.  On early Shermans this was a big complaint, since they did not have a direct telescope yet. You couldn’t really take advantage of the M3 75mm guns range with this sight setup either since it had no magnification. The later better periscopes like the M4, M4A1 and M8 series would all fit in the old mount though.

 659_003

The M4A1 Periscope Sight

Next came an improved version of the M4, the M4A1, and they came with an M38A2 telescope, this one was magnified, but not much at 1.44x, and a 9 degree field of view. Later versions of this periscope had illuminated reticles. The mount was not improved though nor was the linkage.  The M4A1 periscope was changed when the 105mm and 76mm armed Shermans came online, when used with these guns, they had the M47A2 for the 76 tanks, and M77C for the 105 tanks. Hunnicutt doesn’t specify if these were also 1.44X. This periscope was found on M4A1, A2, and A3 76 tanks during WWII.

 m4a1-peridcope-76mm-guns

The M8/M8A1 Periscope Sight

The M4A1 periscopes were replaced by the M8 and M8A1 periscopes. They were a lager tougher improvement on the M4 series, and had the M39A2 telescopic reticle for use with the 76mm gun, since it had the same reticle as the M47A2 used in the M4A1 periscope.  The M39A2 had 1.8x magnification, and a 6 degree FOV.  Even though at this point this was no longer the primary sight, the Army kept improving it. But the mount and linkage still remained an issue.

 s-l225

The M10 Periscope Sight

The Army came up with another new periscope sight system called the M10. They started issuing it late in the war around the same time wet tanks start appearing. This was a much improved periscope; it incorporated two telescopes with reticles, one 1.x, with a field of view of 42 degrees, ten minutes for engaging close targets. The second periscope had a 6x telescope with an 11 degree 20 minute field of view. This periscope could be used with the 76, 75, and 105mm guns when the right reticle was fitted. There was also an M16 periscope, pretty much the same as the m10, but with a reticle adjusting system.

M10C was specific to 75mm Shermans.

M10D was used on 76mm tanks, and 105 tanks.
m10f-periscope-for90mm-apps m10f-periscope-for90mm-appsback 

recticles-for-m10f-periscopes

The Periscope mount

for these periscopes were improved greatly when the 76mm gun and 105 tanks arrived, and the mount was made from a beefy casting, and all the linkage was made much stronger will ball bearing in all the pivot points. These would have shown up on M4A1 75w, M4A3 75w, M4A3 105, M4 105, and M4A3 76w, M4A2 76w and M4A1 76w tanks.

austerlitz_parade
You can see the old style periscope mount in this shot.

This improved mount was also incorporated into most of the post war rebuild and overhauls. It is very easy to spot, by the heavy cast iron hood over the periscope hole.

marine_m4a3_sherman_of_the_5th_tank_battalion_in_ditch_iwo_jima
In this shot you can see the improved heavy duty gunners periscope mount, spikes optional.

The Telescopic sights.

The Shermans fire control system was improved further by the incorporation of a direct telescope mount to the M38A1 gun mount. This prompted the creation of the full length gun mantlet to protect the scope. When these were retrofitted into older tanks, sometimes they would weld on armor over the scope, leaving a half armored mantlet.

The later 76mm armed tanks had the M62 mount, and it had a telescopic sight mount from the start.

The direct scopes went through their own evolution, and this information is put together from the various TMs on the tanks and Hunnicutt’s Sherman, and is not complete. I will update this section as I get more info on the topic.

The M55 Telescope: The first! For the 75mm and 105

This telescope had 3x magnifications with 12 degree 19 minute FOV. This sight was also used on the early production 105 tanks and most 75mm Shermans.

m55

The M51: Also the First, but for the 76 M1A1

The same scope as above, with the same specs, but with the reticle for the 76mm guns, and that’s all. There were complaints about the optical quality on these scopes, since the clarity wasn’t optimal.

M70 Telescopic Sight

The M50 sights were replaced with the M70 Series sights, the same size and magnification. What set them apart was there superior optical quality. The Army went on to develop many different versions of this sight. It was a 3X scope with a 12 degree 19 minute FOV.

M70F Telescopic Sight

This was version used on M4A3 75W Shermans.

m70fusedon75mmmtanks m70frecticle75mmsherman

M70G Telescopic Sight

This sight was used on M10 GMC tank destroyers.

M70P Telescopic Sight

This sight was used on some M36 CMCs tank destroyers.

M71D Telescopic Sight

This was a 5x with a 13 degree FOV version of the scope. It had the reticle for the 76mm guns and was used on those tanks. This was the sight commonly found on M4A1 and M4A2 76 tanks.

m71d-for-76mm-armed-shermans recticle-for-m71d

M71G Telescopic Sight

This version of the M71 was issued with the Jumbo tanks.

M72D Telescopic Sight

This was used on the 105mm armed Shermans.

M76F/D Telescopic Sight

These telescopes were used on the M36 GMC tank destroyers.

m76f-90mm-sight m76f-90mm-sight-2

M76G Telescopic Sight

This scope only had a 3x magnification, with a 21 degree, 30 minutes FOV, and was used in 105 tank applications later in the war.

M83 Veritable Power Telescopic Sight.

This scope had two settings, 4x 7 degrees, 40 minutes and 8x 4 degrees, 15 minutes, and M83D version of this sight worked with the 76mm guns when in an M62 mount. I have not seen this one mentioned anywhere but Hunnicutt’s Sherman book. That doesn’t mean it didn’t get issued as a replacent later in the war, since I’m going off TM’s and spec sheets and those are a small snapshot into a tanks actual combat gear.

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Indirect Fire Control Gear

You would think that would be it for fire control equipment, but it’s not, because all Shermans came equipped with the equipment for their tanks to work as impromptu artillery batteries all Sherman based TDs had this gear as well. The US Army had this extra gear installed all the way up to the M60 tanks. During the war, some tank and TD battalions were very good at being artillery; other units didn’t train for it, and were not good.  This was a good way of keeping tanks useful in Italy, and they filled this role a lot there. I do not think this was something many other nations did with their tanks.

Azimuth Indicator M19

The Azimuth Indicator was mounted near the gunner, right behind the traverse control. This device was used to dial in what direction the gun needed to be pointed in to carry out the fire mission.

azimuth-indicator

Gunners Quadrant M1

The Gunners quadrant is a portable precision instrument used for measuring the elevation or depression angles of guns and howitzers. It can also be used for checking the adjusting of elevation devices on sighting equipment furnished with a gun or howitzer. This was taken right from the Characteristics in tech manual 9-1527.

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Elevation Quadrant M9

The Elevation Quadrant M9 was used to lay the tanks main gun in elevation for indirect fire. There are detailed instructions for setting it up in TM 9-748.

m9-elevation-quad

A Sherman unit trained in how to act as an artillery battery would probably be told they were on call when not in direct combat but close enough for the 75s to reach. They would have men manning radios in the tanks while other tasks were being done, like maintenance, personal things and eating. When they got the call, the designated battery commander for each platoon would listen to the directions on the arty net or get in direct contact with the spotter. In many cases they would wired into the directly, so they wouldn’t need to worry about radio reception. They would relay the aiming information out the tanks on the radio or phone net and then they would start firing.

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M4 being used as artillery

Once they started firing the hole crew would help feed the gun, and if they were doing it as a common thing they might even have large amounts of ammo unboxed outside the tank, where the driver and co-driver could feed them to the commander who then fed  them to the loader.  The M3 75mm gun worked well in this role, since the barrel had a life in excess of 4000 rounds.

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M4 105 acting as artillery.

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Sources: Sherman by R.P. Hunnicutt, TM9-731b, TM9-731G, TM9-748, TM9-748, TM9-750, TM9-752, TM9-754, TM9-759