The PT Boat Forum

Forum Category: PT Boats of WWII

Forum Name: PT Boats - General

Topic: Semaphore Signal Flags

Can anyone help me with a correct size for signal flags that were used on PT boats. Is it just a standard size? Or were the flags used on PT boats smaller?

We have a former Navy guy who wants to make us a set for our boat (728) and he is unsure of how big they should be. He used to make them when he was in the Navy, but PTboats were long gone by his time.

Thanks in advance

Posted By: twhyte | Posted on: Nov 11, 2008 - 5:34am
Total Posts: | Joined: Unregistered

I was a quaetermaster and used these flags for signaling, but I cannot give you their correct size. However to the best of my knowledge they were"one size fits all"
My un official guess would be approximately about 15 square. You've got me wondering. I hope that someone can give you the correct dimensions. I would like to see if my memory from 66 years ago is intact.


Posted By: Russell Pullano | Posted on: Nov 11, 2008 - 11:15am
Total Posts: 131 | Joined: Oct 23, 2006 - 7:31am

Hello Russ:

Well buddy, not too far off. I have several sets donated by Quartermamsters over the years for the Exhibit. I just measured them. They are 23 x 23. Hope this helps you guys on PT 728...........

Posted By: Frank J Andruss Sr | Posted on: Nov 11, 2008 - 2:11pm
Total Posts: 3171 | Joined: Oct 9, 2006 - 6:09am

In QM school each member of the class was given the cloth flags and dowel rods on which to attach the flags. My son now has my flags so I cannot measure them. However, I am certain that the dowel rods were no longer than 18 inches. The rod handle would have been about three inches. That would leave 15 inches for the flag size. I laid out a 15 inch square on a table. My flags were no larger than 15 inches. Those flags were with me from QM school until I gave them to my son last spring. I am uncertain of the size of the flags in the flag locker. I only worked with them in QM school. I have asked another QM who worked with signaling on a DD if he could remember the size.
I will let you know if I get an answer.

Posted By: QM | Posted on: Nov 11, 2008 - 4:54pm
Total Posts: | Joined: Unregistered

Russ, Frank & QM, thanks for your input.

QM, I will wait until you hear from your buddy until I give him the size.

I will post some photos when the flags are finished.

All the best


Posted By: twhyte | Posted on: Nov 11, 2008 - 6:20pm
Total Posts: | Joined: Unregistered

I was QM on the PT167 for two years. I was also the signalman and used semaphore daily. However the flag size was never an issue. I can say this for sure, requisitioning such items was never easy. We took whatever we could get. There was no official size but I would say(from fading memory) ihat the 23 or 24 inch measurement seems to be right.

Posted By: BobPic | Posted on: Nov 13, 2008 - 9:35am
Total Posts: | Joined: Unregistered

According to the Signalman 3rd Rate Training Manual, the semaphore flags are from 15-18 inches sqaure and on on light staffs about 2 feet long.

So there was some flexibility/variances on the sizes.


Posted By: 29navy | Posted on: Nov 13, 2008 - 3:46pm
Total Posts: 500 | Joined: Dec 28, 2006 - 3:02pm

Once again we are dealing with many differnt Companies that produced these Flags. Of the three sets I have ( donated ) they measure 23 inches. The ends or wooden handles in the three sets measure from 6 inches to 9 inches. Sooo, from the mix of answers, anywhere from 18 to 23 inches would not be wrong.........

Posted By: Frank J Andruss Sr | Posted on: Nov 13, 2008 - 4:29pm
Total Posts: 3171 | Joined: Oct 9, 2006 - 6:09am

I now have the size of my semaphore flags. The flags were attached to a round wood rod. The rod is 17 15/16 inches long; diameter one half inch. The flags are 15 x 15 inches. In QM school we made notches in the rod with a pocket knife where we tied the flags to the rods. There are three ties, one at the top , one halfway down the flag, and one at the bottom of the flag. Twine was threaded through the cloth flag inside the hem and tied to the rod. These flags became our personal equipment with our name stenciled on them.

If anyone is interested in using the flags, we were taught to wrap our thumb and three fingers around the bottom of the rod below the flags, about three inches on mine. The index finger was extended up along he rod.

It is a different subject, but I have not heard from my friend regarding the size of the signal flags. PT's were too small to include a flag locker.

Posted By: QM | Posted on: Nov 14, 2008 - 2:45pm
Total Posts: | Joined: Unregistered

I heard from my friend who served on a DD. He said that his semaphore flags were 15x15. Also as best he could remember, the alphabetical flags in the flag bag measured somewhere from 20 inches to 25 inches. You could take one of these flags and attach them to a wooden rod and have a larger semaphore flag.

Posted By: QM | Posted on: Nov 18, 2008 - 6:55pm
Total Posts: | Joined: Unregistered

Thanks for all of your research guys. I can see that this website is a wealth of information.

We decided to go with the 23 x 23 dimensions.

I will post a photo of the finished product when we get them.


Posted By: twhyte | Posted on: Nov 19, 2008 - 4:10am
Total Posts: | Joined: Unregistered