Carter vs. Secomak Type 447

[Mitch]

I know the much touted advantage of the Carter made 447 hand crank is that it was built with ball bearings, but what exactly sets it apart from the Secomak made version? I've tried searching for old threads going over the pros and cons of each make, but haven't found much information. Is there anyone who's familiar with these sirens that could speak to the durability, loudness, etc of one compared to the other? Thanks!

[JasonC]

According to Adam Smith, the Secomak's had a more loose tolerance between the rotor and stator, lowering the sound output.

[danwisbey85]

Main difference between both type of sirens is build quality. The Carter model was much more robust built and tougher bearings then the Secomak. The secomak was built on a cheaper basis with bearings and gears that easily broke when under too much pressure from turning the handle. I owned both models and boy I can tell you!
The Secomak I owned was a later built model with a special handle device designed to help reduce friction/pressure on the gears when sounding. It worked fine and too me felt very light when sounding and the handle was easy to turn.
The Carter model was much heavier built and more sturdy. When turning the handle you "Felt" a huge difference in weight. Much more stiff and heavy to turn but was much more robust to take a hammering so to speak.
Personally would recommend the Carter model over the Secomak.

[Mitch]

Main difference between both type of sirens is build quality. The Carter model was much more robust built and tougher bearings then the Secomak. The secomak was built on a cheaper basis with bearings and gears that easily broke when under too much pressure from turning the handle. I owned both models and boy I can tell you!
The Secomak I owned was a later built model with a special handle device designed to help reduce friction/pressure on the gears when sounding. It worked fine and too me felt very light when sounding and the handle was easy to turn.
The Carter model was much heavier built and more sturdy. When turning the handle you "Felt" a huge difference in weight. Much more stiff and heavy to turn but was much more robust to take a hammering so to speak.
Personally would recommend the Carter model over the Secomak.

Can you attest to the difference in loudness between the two that Adam Smith claimed? I vaguely recall what Jason C is referring to, but I can't say for sure.

[danwisbey85]

I can confirm that yes, the Carter was much louder because the cogs and gears gripped very tightly. Again the siren was very stiff in turning because of the robustness construction. Once it got going up to speed it was very loud and easy to operate.
The secomak was much easier to start but to me seemed and felt much looser meaning you had to wind it faster to get the sound output matched.

I don't have them anymore but here are my video's...You easily notice a output difference!
Carter:
http://www.youtube.com/watch?v=h9qP8VJ1i1g
http://www.youtube.com/watch?v=I9rPwaW62L8

Secomak:
http://www.youtube.com/watch?v=vXDPBPFiNMw

[Mitch]

I can confirm that yes, the Carter was much louder because the cogs and gears gripped very tightly. Again the siren was very stiff in turning because of the robustness construction. Once it got going up to speed it was very loud and easy to operate.
The secomak was much easier to start but to me seemed and felt much looser meaning you had to wind it faster to get the sound output matched.

I don't have them anymore but here are my video's...You easily notice a output difference!
Carter:
http://www.youtube.com/watch?v=h9qP8VJ1i1g
http://www.youtube.com/watch?v=I9rPwaW62L8

Secomak:
http://www.youtube.com/watch?v=vXDPBPFiNMw

That makes me feel better about selling the Secomak I had a while back. I spent hours bringing it back to decent shape, but sold it ultimately because I could break even with it and buy a Carter to permakeep later on.

[CrazyCalvinWilliams]

Hey Mitch, that^was your 100th post! :thup:

[Mitch]

Another question to anyone familiar with the history behind the Carter and Secomak hand cranks...

I've come to learn that these sirens were used by the Royal Observers Corps at outposts to warn local populations. What doesn't seem to be clear, however, is during what time periods these were used. Many claim they began seeing use in World War 2, and Adam Smith stated they began manufacture in 1939, but ROC history websites seem to exclude them from WW2 era pages. I can find some info regarding their use in the Cold War, plus the Secomak's user manual explicitly dictates the intended signal codes for nuclear fallout warning (something that obviously wouldn't be used in World War 2). What also isn't clear is what types of outposts got issued these things, because only 9,000 out of 19,000 ROC monitoring outposts were given hand operated Type 447 sirens. Any clarification on this is appreciated.

[Adam Pollak]

I have a Secomak I got about 10 years ago. The gear noise is almost as loud as the siren itself. There is a tolerance of around 1/4" which means it essentially is just leaking air. It makes a siren noise and the damper in front does create a pulsed signal of sorts, but by no means loud.......though fun.

[Mitch]

After restoring both makes of the hand crank 447 siren, I am confident in saying that the assertion the Carter siren is any more "robust" or durable than the Secomak is a flat out myth.

There are differences between them, and which one you look for boils down to personal preference. However the issue lies with people saying that the Carter sirens are more robustly built, primarily due to the use of ball bearings on the rotor. First off, the Carter doesn't use a true ball bearing system. What would be an inner race of the ball bearing is all that exists, and it sits inside an equal size cut-out on the stator piece suspending the rotor holding it in place. Same goes for behind the rotor where it meets the gearbox. The problem therein is that those bearings end up being fragile, especially when taking apart the siren for maintainance. The Secomak by contrast skips fitting the bearings onto the end tips of the rotor shaft, and instead lathes down both ends so that they act like pins that just slide into equal diameter holes. Visualize a shallow divot for the ball races of the Carter, and deeper but less wide pin holes for the Secomak. Solid metal is holding that Secomak rotor in place, not half a ball bearing as with the Carter. The gears themselves are *identical* between the two, the only difference lies with how they go about affixing the rotor securely in place. The durability advantage lies with the Secomak.

The Carter does however have a quieter, and smoother operation. I noticed the Carter coasted a bit longer than my Secomak (which even has the roller clutch handle). As for loudness of the siren mechanism itself, that's debatable. They both have the same apparent tolerances, rotor/stator clearance, and overall loudness when cranked at the same speed.

Just thought I would share my findings since even the ROC history society was perpetuating the idea that the Carter is somehow more durable.