Carrier armour manufacturer?

[Lynn Eades]

Rob, maybe the hardening and straightening process changed the steel dimensionaly enough, so a to be sub standard?
The guys (and girls) involved from start to finish should have been proud of the quality end result.

[Bob Phillips]

I would like to throw a little information out about SDA - GALT.
I grew up in Galt about 3 blocks from the SDA plant. My neighbor was a traveling saw salesman and saw hammerer.In addition to a wide variety of handsaws SDA made the large ( 4 foot diameter) sawblades used in commercial sawmills. These type of blades are not flat but slightly dished so that at high speed they straighten out and run true. A saw hammerer was a skilled craftsman who traveled to service saw blades across Canada, and hammer them to run true again.
My mk2 carrier also was clearly labelled SDA GALT. The company closed 25 years ago ( maybe longer than that) and today the site is occupied by the new
Dunfield theater. Next to it is the large antique mall ( worth a walk through !!) that used to be the old Babcock - Wilcox- Goldie McCullough foundary where they made all manner of farm equipment, milling machinery, vault doors and safes etc. Back when we had industry close to home...B.P.

[rob love]

So Bob (and all), would the hammering marks on the armour be from a hand held hammer like a blacksmith's hammer, or was it more of a mechanised hammer forge type affair. I had assumed it was likely the latter, but when you talk about a travelling "saw hammerer" you almost make me think of a guy with a small chest of tools driving from mill to mill.

[Gordon Yeo]

The circular saw blades that Bob refers to had removable teeth that could be resharpened or removed when worn down or damaged. Keeping the saw running true in the kerf required it to have no distortion of the blade. If a spot on the blade over heated from excess rubbing and caused an expansion (bubble ) the saw would wobble beyond control and be unserviceable. This is where the saw hammerer services would be required. With proper training the hammer could hammer the steel back into its "flat" configuration and make the saw blade serviceable again. That is what must have been required to be done the armour plate for the carriers to flatten it.

Now, it's one thing to hammer a small area of a 3/16" thick saw blade back to flat by hand but it must have been a whole lot more complicated to hammer thousands of heavy carrier and Sexton plates.

[RichardT10829]

I always thought they were pressed flat again the forks were positioned over high spots before activating the press.

[Bob Phillips]

Well I have to admit I do not know what they used to straighten armor plate but I would assume it was done in some sort of press. Hammering a 48 inch saw blade by hand is one thing but mass armor production is another.
Unfortunately I do not even know of any of my old neighbors who are alive to ask! Pity I didn't think to ask 30 years ago when a few old timers were still about!

[rob love]

I had to straighten some of the front shields on my 105 howitzer due to rollover damage when they were in service. They will often have those hammering marks as well. The press will only go so far before you hear a "crack", and sure enoguh, there will be a crack in the armour. I ended up heating them red to bend them straight, likely destroying the temper on the hard side. If there is ever a next time I'll try the hammering method.