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Wednesday, July 2, 2014

Technology of the Revolutionary War

As we celebrate this Independence Day weekend, let's examine one of the weapons used on the battlefields that forged this nation that was as popular as it was innovative.  Having some small mobile cannons to aid your cause was not a new idea in the Revolutionary War.  It extends nearly as far back as the cannon itself, even predating the first handheld firearms, and the success of such guns can be traced to the 17th century.  The less powerful nature of small artillery made them ideal as anti-personnel weapons and they would often accompany infantry as a maneuverable addition of firepower and psychological edge. Periods of time would come where large artillery was the preference, but the mobility and speed of smaller field guns always would seem to win out.

For centuries, field artillery largely relied on iron barrels because they were strong, cheap, and easy to make.  What was then viewed as a critical component, iron, would stagnate fighting tactics in Europe for centuries thanks to its weight.  If you wanted more powerful guns, by necessity they had to be larger.  However, as it has been proven over and over, it would only be a matter of time before modern technology would change the battlefield.

Lot 2100: Revolutionary War Style Verbruggen Three Pound "Grasshopper" Cannon with Carriage

Technology of the Grasshopper

What was the leading battlefield technology by the 1700s?  Bronze.  This is a funny coincidence since people had been using bronze for centuries, nay millennia, before iron was used, and because using bronze for cannons was not a new idea at all.  The Chinese had done so almost four centuries earlier.  That precious mixture of 90% copper and 10% tin was not only more expensive than iron, as most "new technologies" are, but also heavier.  Thankfully, due to its flexibility and increased strength, less of it was needed to construct barrels, thus resulting in an overall lighter weapon.  By the mid 1700s big, heavy artillery pieces were quite popular.  The line of heavy guns would set up as a line and fire throughout the battle.  They were powerful, stationary, and intimidating.  However, smaller cannons could be maneuvered more easily for a number of purposes.  Want to attack a certain point in the enemy lines?  Soften it up with cannon fire first.  Need to reinforce a weak spot in your own lines?  Move some cannons over there.  Wish to conceal some troop movements?  Fire your cannons and let the smoke hide them.  Smaller guns could adapt to the changing needs of a battle, giving them more uses, and making them much more valuable.

Not only was bronze lighter than iron, but it had many other desirable metallurgic qualities.  Its flexibility meant that even in a catastrophic failure, it may rupture, but it wouldn't explode sending dangerous fragments into its own ranks.  Lighter weapons also meant less animals to transport them, less care of said animals, and as the British found in the Revolutionary War, they were much easier to transport on America's dismal roads.  The fact that bronze cannons could be melted and reused, while iron cannons had to be scrapped, was another side benefit.



Speaking of the British, they officially had been using more 3-pound guns ("grasshoppers") as far back as 1686, but other innovations had also improved their performance, namely that of the boring mechanism via what is now known as the Martiz method.  Instead of a casting the guns vertically around a core to create a barrel, solid cannons would be bored using what was essentially a large lathe.  This resulted in higher accuracy, more precisely fitting projectiles (less windage), faster production, less gun powder required for each shot, and the ability of armies to field many more cannons.  Another new technology utilized in the Grasshopper was that of the spherical powder chamber, which allowed for a more rapid combustion that in turn resulted in more power and less powder being used.

All that considered, you're looking at what is almost the pinnacle of battle field technology in the 1700s.  With its newly utilized materials, rethought powder chamber, increased safety, and ease of transportation, it was certainly the envy of armies still relegated to using heavy, less accurate, iron artillery.  These new 3-pounders were nicknamed "Grasshoppers" for two reasons.  The first was their appearance on the battlefield.  Moved via handspikes (a.k.a. "big levers for moving stuff") they would flit forward and backward on the battlefield like a grasshopper.  It is also said that, when fired, they jumped back like a grasshopper.  It's not certain how their recoil would have been different that any other cannon, but the story remains.

Moving a Grasshopper via the "Irish Method"


Details of the Grasshopper

First things first, this particular cannon, to be sold in Rock Island Auction Company's July 2014 Regional Firearms Auction is an excellent reproduction made in the 1960s.  This type of cannon is known more generally as a "3-pounder" because it fires a 3-pound ball (give or take several ounces) of solid lead.  With such a round, troops could typically expect between a 800 - 1,000 yard range, but with grapeshot the range dropped to 600 - 700 yards maximum, and to 200 - 350 maximum for canister shot.

The three numbers shown in the picture below indicate the Grasshopper's weight.  The first digit tells the "hundred weight" (112 lbs), the second tells "quarter hundred weight," and the last digit is for pounds.  That in mind, a reading of 1:3:10 tells us that this barrel weighs 206 pounds (112 + (28 x 3) + 10).  This is a significant reduction in weight from previous barrels (sometimes more than half) and must have been a surprising sight to a likely skeptical artillery man seeing it for the first time.



This gun also shows the "broad arrow" (a.k.a. "crow's foot") which was placed to indicate ownership by the British military and was used between 1717 - 1800.  The cannon's measurements are:

Length: 40 1/2"
Width: 11"
Trunnions: 2 1/4"
Bore: 3"



Upon investigation of the markings on the cannon, one will also notice the words "I. & P. VERBRUGGEN."  These are the makers Jan Verbruggen (indicated by the "I") and his son Pieter.  He was born in 1712 and is alleged to have quite a knack for drawing at an early age.  No one knows how that talent was harnessed for manufacturing artillery, but by 1746 Jan was the master founder of the Dutch Admiralty's bell and cannon foundry in Enkhuizen and soon after that he was also made the master gunfounder.  His eldest child and only son, Pieter, was born in 1735 and shared his father's knack for art and foundry.

The year after Jan was made the master gunfounder, the Dutch Government finally adopted the aforementioned Martiz system (the lathe-like creation technique) of creating cannons and by 1755 Jan's hard work and abilities were again recognized as he was named the master founder at the National Heavy Ordnance Foundry at The Hague.  Jan & Pieter remained there until 1770 when the story takes an interesting turn.  Some sources say that Britain, in an effort to improve their ailing manufacturing abilities, turned to Jan and obtained the services of the father/son duo.  The two would eventually all but rebuild the entire Royal Brass Foundry at Woolwich and turn it into one of the top producers in the British Empire.



The other story of the Verbruggens leaving The Netherlands and their string of successes there is that the pair was virtually run out of the country for concealing flaws in their cannons.  It all started when Verbruggen destroyed the imperfect furnace of his predecessor and replaced it with one of his own design.  This created an instant grudge with the Inspector General of Artillery, away on business at the time, who thereafter resolved to pay back Verbruggen for the offense.  It didn't take long for accusations to fly that the two Verbruggens would alter and repair their cannons between the boring and proofing stages to hide errors in the casting process.  Granted, these corrections were more common than people at the time liked to admit, and the accusations were made by two men whom Verbruggen had previously fired, at least one of which had an excellent reputation as a founder.  Verbruggen was successfully defeating the accusations as more and more cannons were found NOT to have the claimed defects and repairs, but numerous dangerous repairs were found in a third investigation.  Numerous screws were found used to fill in imperfections along with many other plugs, repairs, uneven metal composition, and various unsafe defects which would make the guns unreliable and even dangerous to use.  Despite Verbruggen's claims that the barrels were sound and that the repairs were only made to keep a high trust in his product (not true), he knew he would not keep the position.  As legal procedures were being formulated for his removal, he took the post in Woolwich and resigned that in the Netherlands.

Whether one wishes to focus on the Machiavellian drama that was certainly unfolding in the foundry at that time or rather on the fact that Verbruggen was making unsafe repairs, the end results are the same: he left the Netherlands, took over for Britain, and revitalized Woolwich - a facility long overdue for a cleaning, new equipment, and new methods.  This finished revamping of the Woolwich facility in 1773 was so effective that the British Government allegedly classified it as "secret," despite the fact that several other nations had already been actively using the Martitz Method for over a decade.  It then promptly cancelled all of its contracts to private foundries for brass and bronze cannons feeling that their new methods would be adequate to meet their manufacturing needs.  Their production prowess would soon be put to the test thanks to a group of unruly Colonials.






Sources

http://www.americanrevolution.org/artillery.html

http://www.napoleon-series.org/military/OrdnanceJournal/Issue6/SOJ-6-6_C18th_Gunfounding.pdf

Strach, Stephen G. "A History of the Three Pound Verbruggen Gun and Its Use in North America: 1775 - 1783." Thesis. 1986. Print.

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