Editing M4 Sherman (section)

==Mobility==
[[File:Volutespring.jpg|thumb|[[Vertical volute spring suspension|Vertical volute springs]] of [[Stuart tank]] with similar suspension system]]

In its initial specifications for a replacement for the M3 medium tank, the U.S. Army restricted Sherman's height, width, and weight so that it could be transported via typical bridges, roads, railroads, and landing craft without special accommodation. Army Regulation 850-15 initially restricted the widths of a tank to 103 inches (2.62 m) and its weight to 30 tons (27.2 t). This greatly aided the strategic, logistical, and tactical flexibility and mobility of all Allied armored forces using the Sherman.<ref name="autogenerated302">{{cite book |last1=Green |first1=Constance McLaughlin |last2=Thomson |first2=Harry C. |last3=Roots |first3=Peter C. |title=The Ordnance Department: Planning Munitions for War |date=1955 |publisher=United States Army Center of Military History |location=Washington, D.C. |page=302 |url=https://history.army.mil/html/books/010/10-9/CMH_Pub_10-9.pdf |archive-url=https://web.archive.org/web/20120927115505/http://www.history.army.mil/html/books/010/10-9/CMH_Pub_10-9.pdf |url-status=dead |archive-date=27 September 2012 |access-date=21 May 2020}}</ref>

A long-distance service trial conducted in Britain in 1943 compared diesel and gasoline Shermans to [[Cromwell tank]]s ([[Rolls-Royce Meteor]] engine) and Centaur ([[Liberty L-12]]). The British officer commanding the trial concluded:
{{blockquote|They are utterly reliable.....I do not think they are quite as good as the Cromwell across the country when they are running on rather worn rubber tracks and the going is greasy, neither does one get as smooth a ride, but they appear so infinitely superior in every other way particularly in reliability with a minimum of maintenance that this cross-country consideration is completely overweighed.{{sfn|Moran (7 May 2014) Exercise Dracula}}}}

The Sherman had good speed both on and off-road. Off-road performance varied. In the desert, the Sherman's rubber-block tracks performed well, and in the confined, hilly terrain of Italy, the smaller, nimbler Sherman could often cross terrain that some heavy German tanks could not. [[Albert Speer]] recounted in his autobiography ''Inside the Third Reich'':

{{blockquote|On the southwestern front (Italy) reports on the cross-country mobility of the Sherman have been very favorable. The Sherman climbs mountains our tank experts consider inaccessible to tanks. One great advantage is that the Sherman has a very powerful motor in proportion to its weight. Its cross-country mobility on level ground is, as the 26th Panzer Division reports, definitely superior to that of our tanks.<ref>{{cite book|last=Speer |first=Albert |title=Inside the Third Reich |publisher=Ishi Press |year=2009 |isbn=978-0-923891-73-2 |chapter=chapter 17, 2nd note}}</ref>|sign=|source=}}

However, while this may have held compared with the first-generation German tanks, such as the Panzer III and Panzer IV, comparative testing with the second generation wide-tracked German tanks (Panther and Tiger) conducted by the Germans at their [[Kummersdorf]] testing facility, as well as by the U.S. [[2nd Armored Division (United States)|2nd Armored Division]], proved otherwise. The M4's initial tracks were 16.5 inches wide. This produced ground pressure of 14 pounds per square inch.<ref name="autogenerated302"/> U.S. crews found that on soft ground, the narrow tracks of the Sherman gave poorer ground pressure compared to the Panther and Tiger.

Because of their wider tracks and use of the characteristic ''Schachtellaufwerk'' interleaved and overlapped road wheels (as used on pre-war origin German half-track vehicles), the Panther and Tiger had greater mobility on soft ground because of their greater flotation (i.e., lower ground pressure). Lieutenant Colonel Wilson M. Hawkins of the 2nd Armored Division wrote the following comparing the U.S. M4 Sherman and the German [[Panther tank|Panther]] in a report to Allied headquarters:

{{blockquote|It has been claimed that our tank is the more maneuverable. In recent tests, we put a captured German Mark V [Panther] against all models of our own. The German tank was the faster, both across the country and on the highway, and could make sharper turns. It was also the better hill climber.{{sfn|Green|Brown|2007|p=53}}}}

This was backed up in an interview with Technical Sergeant Willard D. May of the 2nd Armored Division who commented: "I have taken instructions on the Mark V [Panther] and have found, first, it is easily as maneuverable as the Sherman; second [[Panther tank#Suspension|the flotation]] exceeds that of the Sherman."{{sfn|Green|Brown|2007|p=53}}

Staff Sergeant and tank platoon sergeant Charles A. Carden completes the comparison in his report:
{{blockquote|The Mark V [Panther] and VI [Tiger] in my opinion have more maneuverability and certainly more flotation. I have seen in many cases where the Mark V and VI tanks could maneuver nicely over ground where the M4 would bog down. On one occasion I saw at least 10 [[Tiger II|Royal Tigers]] [Tiger II] make a counterattack against us over ground that for us was nearly impassable.{{sfn|Green|Brown|2007|p=53}}}}

[[File:A Sherman tank of 8th Armoured Brigade in Kevelaer, Germany, 4 March 1945. B15145.jpg|thumb|right|A Sherman with track widening "duckbill" extended end connectors]]

The U.S. Army issued extended end connectors ("duckbills") to add width to the standard tracks as a stopgap solution. Duckbills began to reach front-line tank battalions in fall 1944 but were original factory equipment for the heavy M4A3E2 Jumbo to compensate for the extra weight of armor. The M4A3(76)W HVSS Shermans and other late models with wider-tracked suspensions corrected these problems but formed only a small proportion of the tanks in service even in 1945.