WW I Era NAVY Plane LANG Co Wood Propeller CURTISS HS LIBERTY

[Jeff F]

Hello All
Thanks for the great website and forum , I have got a good start learning about props from this site.
I have listed on ebay a Lang Products Co. prop that i would like to learn more about. I understand the common markings on it but there are other markings that i hope to learn more about.
There are alot of markings on this so I will try to go in some order , top of hub is marked " N 597 " and " TM ' which is also the only marking on other end which i believe stands for Tractor Monoplane , On the main face of the hub starting from left in photo is a navy " Anchor US " symbol then " MD " in a circle then " RNA " , Around the hub reads " DRG No S.E. 5090 , L.H. H.P. 370 Liberty Motor Lang Products Co. No 5440 , Pitch 6.65 DIA 8 - 4 " . Then there is " RDW " then two lines of words or letters i can't make out above " U.S. NAVY " . I tried pencil impressions and lighting and angles for an hour and its to weak to make out but first two letters looks like " M.T. _ _ _ _ "next line looks like " RES _ _ _ " then third line is " U.S. NAVY '. Interesting that this has two Navy markings and maybe what i cant make out refers to decommissioning. The back side of the hub has only one capitol " X " marked about 3 inches onto the wing at center from hub toward damage , which should be seen best with the zoom function in the 8th photo. There is cork filler in the mount holes on backside of hub. The hub is 8 bolt and aprox 12 inches tall 3 3/4 thick with a 3 1/4 opening.
I 'am interested in any more specific info of it's application and on the following markings the " N 597 ' on top of hub , the " MD ' in circle , the " RNA " , the " RDW " and the single " X " on back of the hub also any info on the Lang sticker which is different than others i have found and what this might tell.
I will post the hub shots here but for all 12 photo's with zoom i hope i don't offend by asking you to go to my listing and take a look. If you search this title on the Bay you will find it " NAVY Plane LANG Co Wood Propeller CURTISS HS LIBERTY " . Thanks in advance , Good Day

[Dave]

I've seen quite a number of those, all apparently sold off as surplus in the early twenties. It's actually half of a 4-blade "stacked" combination used on the Curtiss HS2L pusher flying boat with the Liberty 375 HP engine. The "L" in the HS2L denotes a Liberty engine, as earlier models used something else (maybe a Hisso, but I don't remember). The hub is half the thickness of a normal Liberty engine hub (just under 4") so that it can mate with the other half. Note that it is a left hand thread and used in a pusher configuration, so I'm still not sure what the "T.M." stands for, and may never know. There was a 2 blade version, but it had a different numerical sequence than the S.E. 50x0 on yours, where the 3rd digit indicated pitch. Incidentally, the "S.E." stands for "Steam Engineering", which was the Navy department responsible for procuring aircraft propellers.

As I recall, Lang was one of several different manufacturers that supplied those to the Navy.

I've owned (and sold off) several of these. At one time I saw a consecutively numbered pair, which unfortunately got sold separately. Go to this page for some more information.

[Jeff F]

Hello Dave
when you say you have seen or sold several of these you mean Curtiss HS2l 's in general and not this exact prop , maker and markings i assume , so my question would be do collectors give any value to different makers or production numbers , year made , ect or do all props for a particular engine carry the same weight in collectors eyes.
This one is marked 370 hp not 375 and it only has 8 bolts not 9 like the one in the example you referred me to?.
Thanks for your response

[Dave]

There was a lot of variation among manufacturers even among production lines of the same manufacturer sometimes. The ninth hole in the hub was a partially drilled hole for an alignment pin, but wasn't really necessary. It also is not unusual to see horsepower stamped differently.

I think the value of yours is adversely affected primarily by the water damage and rot on the blade, but the decal is in nice condition, as is the remainder of the finish, so it would make a good display propeller if someone is willing to accept the damaged features.

I don't think for this particular model prop that production numbers, manufacturer, etc. have any real effect on value. Matching blades would carry the highest value by far.

[Dave]

Incidentally, you will get several fold more traffic on eBay if you use "wooden" propeller in your title and description instead of "wood" propeller.

[Jeff F]

ww1 Lang prop

Thanks for that last bit of advice.
I have got a question from someone about the notches in the hub , one on each side or top and bottom of different size and location that look to me like they are from the manufacturer as they are smooth but have no stain. I will add a few pictures that show them here.
Last question would be can you place an exact date/year or range by the markings. Thanks Much

[Dave]

I think the notches are from laminations (perpendicular to the obvious laminations seen on the hub) that have separated, and the piece has been lost. A number of these particular models have shown various stages of delamination. I don't know whether that's because of the glue breaking down over time or some characteristic of the wood that stressed the joints.

To my knowledge, there is no record of dates of manufacture for these. I do know that a number of them were sold off as surplus in 1921.

[Jeff F]

Dave

Dave
Thanks for all your help , i really appreciate you taking the time to share your knowledge with me.
Take Care , Jeff