I cannot look at a .303 SMLE (Short, Magazine, Lee-Enfield) without having the stereotypical image of an Indian constable pop to mind — overweight, disillusioned, possibly a trifle dishonest, but often brave when it counts the most. If he’s armed, there’s a good chance that he carries a .303 SMLE. You may have seen him on the street, at the airport, railway station, so many places. In my mind’s eye, he treats his rifle as though it is unloaded; I also suspect that it wouldn’t pass a thorough arms inspection.
The constable’s SMLE was one of the 20th century’s outstanding military rifles and surely the one with the longest service record. Adopted by the British Army at the turn of the century, the .303 Lee-Enfield saw service in both world wars and countless conflicts around the world. During World War I alone, more than 2,000,000 SMLEs were made at the Royal Small Arms Factory at Enfield Lock, Middlesex (Reynolds 1960: 180). These rifles would eventually be manufactured at factories in England, India, Australia, and even a few in the United States. Production changed to the 7.62 cartridge in the 1960s, and the last Enfields were made in the early 1970s.
My favorite is the .303 SMLE No. 1 Mk III; to me it is the quintessential smallarm of the world wars. With an overall length of 44.5 inches and weighing a little under 10 lbs, its Mk VII ball cartridge delivered 2,450 fps at the muzzle (Stratton 2009: 5, 140).
The British Army adopted the .303 SMLE No. 1 Mk III in 1904 and the Indian Army soon followed. The Ishapore Rifle Factory, north of Calcutta, began manufacturing this weapon in 1909 using British machines and the same specifications as that followed by the Royal Small Arms Factory. At what must have been its production peak, Ishapore made 600,000 SMLE No. 1 rifles during World War II (Stratton 2009: 4).
The .303 Enfield was continually improved throughout its long service life. This striving for perfection is undoubtedly why, even today, one can occasionally find .303 Enfields on the world’s battlefields. They were good, dependable, and effective rifles. For example, during the Soviet-Afghan War of the 1980s, mujahideed found through practical experience that the .303 Enfield had twice the effective range of the AK assault rifle and could punch through Soviet flak jackets (Jalali and Grau 1995: 244, 400). While it was obviously an obsolete antique, Soviet soldiers learned to respect the .303 Enfield.
More recently, several Indian constables armed with .303 Enfields were among the first responders during the November 2008 terrorist attacks in Bombay. Sadly, most of these weapons jammed after firing a few rounds and did not contribute significantly to the running fire-fight that raged across South Bombay. The main cause of weapon malfunction appears to have simply been poor maintenance (Badri-Maharaj 2009: 151). The November 2008 terrorist attacks taught several hard lessons. Among them, it is clear, and has been clear for a long time, that the Indian constable deserves a more effective weapon and better training for combating increasingly well-armed criminals and urban terrorists. The .303 SMLE was a great rifle in its day, but its day is well past.
References Cited
Badri-Maharaj, S. (2009) The Mumbai Attacks–Lessons to be Learnt from the Police Response. Journal of Defence Studies, 3(2): 145–156.
Jalali, A.A. & L.W. Grau (1995) The Other Side of the Mountain: Mujahideen Tactics in the Soviet-Afghan War. Quantico, VA: United States Marine Corps, Studies and Analysis Division.
Reynolds, E.G.B. (1960) The Lee-Enfield Rifle: Its History and Development from First Designs to the Present Day. London: Herbert Jenkins.
Skennerton, I.D. (2007) The Lee-Enfield: A Century of Lee-Metford and Lee-Enfield Rifles and Carbines. Labrador, Australia: Ian D. Skennerton.
Stratton, C.R. (2009) British Enfield Rifles, Vol. 1, SMLE (No.1) Mk I and Mk III. 3rd edition. Tustin, CA: North Cape Pubs.
Links
- Top Ten Combat Rifles: Lee Enfield SMLE – The SMLE takes the #3 position behind the AK-47 and the M16; (Military Channel video)
- The Short Magazine Lee-Enfield Rifle (S.M.L.E. – A good overview of the SMLE from the UK N.R.A. Historic Arms Resource Centre
- Rifle Factory Ishapore – The Factory’s website, which includes photos and a short history
- The Indian Army’s .303 Story – Reminisce about the .303 Enfield with Aakar Patel
I have a 303 made in India and it has the tag that says g.r.I Singapore 1928 shtle 111 . are you familiar with this gun? it is no 1 mk
Singapore certainly saw thousands of Short Magazine Lee-Enfields (SMLE) pass through it and they’re still used there for some ceremonial occasions, so it’s not surprising to see an Ishapore SMLE No. 1 Mk III with a Singapore stamp. If there are markings on the right side of the stock, I may be able to tell you more about your rifle if you post a description, drawing, or photo of them.
Barry I have a rifle marked G.R.I. Ishapore 1939 SHTL.E III and I want to know where I can get parts for it. I just need the butt plate and sling. It has a wood stock with the fromnt of the stock black plastic. if that helps.
Thanks
From time to time several gun parts places carry SMLE III butt plates and appropriate slings, for example, https://www.sarcoinc.com and https://www.gunpartscorp.com. The items you mention are not among distinctive Ishapore parts, so a SMLE III butt plate from a different manufacturer may work. I’m hesitant to write with greater confidence because your 1939 manufacture date comes into play here. According to Skennerton, pre-WW II Mark III and III* rifles made at Ishapore are identical to their British counterparts but both countries implemented some manufacturing changes in 1939 to speed up production. Such changes are typical of wartime.
Please note that I have not dealt with either company mentioned above, so caveat emptor.
Barry, not sure what I have in this .303 Enfield but side plate says GRI ISHAPORE 1930 SMILE III
Yes, it says SMILE. My grandfather gave me the gun about 50years ago. Have you ever seen this spelling?
Also I have looked at many, many on internet and have not seen a feature this gun has. There is a pivot piece of metal on gun to move into place as a keeper to not let the shell feed when the bolt is opened. Even seen this? This gun is a mystery.
Thanks,
Randy
Interesting weapon, Randy, but it leaves me with more questions than answers. I have only seen SMLE and SHT.LE on Ishapore Lee-Enfields. If the stamp hit the metal of the butt stock socket just a little off center, then it is possible that SHT.LE could lose the bar on T and make the H look more like M. It’s my best guess. I’d be interested to see a photo of the side plate and of the metal “pivot piece”.
Great article Barry! I have a 1942 dated RFI Enfield along with a couple of RFI bayonets, both short and long, though I mainly collect Indian-made pattern 1937 webbing equipment. I have spent a lot of time trying to decipher the different Indian makers, but there is very little information out there. Bata Shoe Company made a great deal of webbing for the Indian army 1941-1943 and KEF & AEF (both still a mystery) made webbing through to the end of the war. ‘Ca’ also made a great deal of leather, canvas and webbing items during both wars and it has been speculated that the maker’s mark refers to either Cawnpore or Cooper Allen…
Many thanks for your kind words and also for the webbing information. My first field bag, which provided good service (it still survives in a tin trunk back in India), was made out of the same kind of webbing material. It figures that Bata had a webbing contract then; the company made a lot of money out of both world wars. I was astounded to learn recently that Bata’s first plant in Calcutta was not an Indian venture, but expansion by a Czechoslovakian company. It casts my Bata sandals in a new light. KEF and AEF are also new acronyms for me. I’ll keep my eye out for the company names.
My enfield looks EXACTLY like te one pictured at the top. GRI.crown..1950..the nose cap matches the number on the receiver…with a (k) underneath. .the number on the bolt arm doesnt match and ends with an (N) blade site has a C,as well as inside the stock oiler plate..couple of (C)s through out the rifle..some 23 or 32s.id have to site down and write down every spot,crown,number, also a white painted small (36) on tbe left hand of the shoulder stock. .another crown with IS and some hard to see .another crown on left side of receiver with gri (kinda small) and of course #1 Mk3 303 IND. Cia st ALB VT.right side of the bolt protector (my first enfield obviously )..any thing you can tell me about it will be greatly appreciated. .thank you
My apologies for taking a while to respond but I was away from my desk this past week. Now, as for your questions, rifle markings on a widely used weapon that saw many years of service can be a real tangle to interpret. The Skennerton book is an excellent reference and place to begin about Enfields. Here’s what I can tell you about your rifle:
The GRI & crown: An artifact of the India’s British colonial past. India dropped the GRI for RFI (Rifle Factory Ishapore) around 1951 and replaced the crown symbol with the Ashokan lion, the official emblem of the modern republic.
The “N” suffix on the bolt serial number: Serial number letters vary greatly, but “N” was among the letters used on Ishapore SMLE Mk III* serial numbers between 1946 to ~1980s.
The “C” markings are hard to interpret with any accuracy because the letter “C” was used in several different ways. The meaning assigned to a “C” can differ according to the font or shape of the letter, if it is enclosed by a box, a circle, and so on.
The “36” painted on the stock: Probably an arms rack number from when the weapon was in service. I say probably because a previous owner may have succumbed to the temptation to paint a fake rack number on the rifle to give it a more authentic look. It happens.
The furniture: You write that your rifle looks just like the one pictured in the blog post. Does the wood have the same deep reddish color and dense grain? If so, you may well be looking at Indian rosewood of the genus Dalbergia, one of several native woods used at Ishapore. I have no idea how well it served as a rifle stock, but it looks great.
The “Cia st ALB VT” just tells you that the rifle was imported by Century International Arms, St Albans, Vermont.
You mention “some 23 or 32s”. Can you give me more details or a photo?
Often there are markings on the right side of the butt stock that help one to identify where the rifle was in service. Any on yours?
Hi Barry, I have a MK III* that is very confusing, I know it is made in India as it has stamp on barrel and receiver of GRI all serial numbers match, barrel, receiver, bolt, site and pig nose#15390Y. The only place the NO 1 MK III* is stamped is below the screw on the safety trigger side strap, below the model markings is a large FR and small 45 and below that is stamped ENGLAND. The right side below the bolt handle is nothing , just smooth finish that has never had any stampings on it, I have looked a pictures of many Enfield rifles and have never seen one stamped on this side
On the barrel is the stamp w/crown GRI crossed flags and a P, SA27, crossed swards w/small letters/numbers I can’t read in the left, right, and bottom of cross.
Next line is proof stamp Crown w/BNP under , 303 2.222″. Next line is 18.5 tons per
I have owned the rifle since 1970 and is great condition, barrel is super nice condition along with stock, it has a rubber butt pad installed by previous owner. I can not find any info on how to date this rifle so I hope you can help on this. Thanks Bob
Hi Bob. Many thanks for your posts. My best guess based on what you’ve told me of the markings is that it is an early post-WWII Indian rifle that found its way to the UK, from which it was exported to the US sometime between 1954-1968.
As you indicated in your comment, the crown and GRI marks show that it is an Ishapore Rifle Factory product. The “Y” suffix on the serial number occurs on Ishapore Rifle Factory Mk III* rifles manufactured between 1946-1980+ (Skennerton’s The Lee-Enfield, pp. 558-9). The crown and GRI marks narrow the manufacture date to between 1946 and roughly 1951.
The “FR” is an Ishapore marking for a weapon that received a factory repair. The “England” reflects a pre-1968 USA requirement that imported weapons show their country of origin. The left side of the buttstock socket on the action body, where both marks occur, was a typical place for rebuilding or conversion markings according to Stratton’s British Enfield Rifles, p. 30).
The “BNP”, “.303”, and “2.22” on the barrel are British export markings. The crown & BNP (Birmingham Nitro Proof) were used by the Birmingham Proof House since 1954.
New up date: I have now found a glass that allowed me to see the letters in the crossed swords, the letter “K” on the left, the letter “B” on the right and number 6 on the bottom. I know this sign was used from 1950 on and started with the letter “A” but the GRI used on Ishapore proofs was dropped in 1952 and changed RFI, so the “K” date on my rifle doesn’t fit the sequence. Sorry for all the messages and the miss spelled “sight”. Bob
Very helpful information. It is the Birmingham Proof House date mark for weapons proofed in 1959. From this we can narrow down the date that the rifle was imported from the UK to the US to between 1959-68.
Thanks for reply Barry, I would still like to find out when my rifle was made, I know the GRI means before 1952, I will keep looking. Thanks Bob
Hi Barry; I would like to ask you if the FR (factory repair) on my rifle which I assume was done in England as stamped on the rifle. could the 45 next to the FR be the year of repair? sorry for so many requests but this is now becoming a real hunt for the date of birth of this Enfield. I also have a very nice M1 Springfield made in December 1940, which is a companion to the Enfield. Do you notice that both of these famous rifles that won the 2nd WW end in FIELD. Thanks again Bob
The “FR” on the rifle is an Ishapore mark, one that wasn’t used in the UK, so the work was done in India. Like you, I wonder about how to interpret the “45”. It’s tempting to speculate that it stands for 1945, but I decided not to go there when I was looking through the list of marks that you posted because (1) I don’t know how Ishapore handled its FRs, and (2) a 1945 repair date conflicts with the serial number. Also, since your rifle has matching serial numbers throughout, it clearly wasn’t assembled with older component parts, so I can’t jump on that possibility to claim that at least part of it is a 1945 weapon. In the end, it’s just hard to be more specific about the manufacture date without having the rifle in hand.
Hi Barry, thanks for reply. The one thought I have is why is the wrist stamped England (stamped twice as not very good first time) under the “FR”, if repair was done in Ishapore? When you say the “45” conflicts with the serial number, do you mean that my rifles serial number was produced after 1945? , also forgot to tell you the “Y” in the serial number was under it. I hope I don’t make you a little crazy with this. Thanks Bob
Hi Barry, now I know I’m the one going nuts, I just re-read all you reply’s and don’t know how I missed the fact that you said the England stamp is for export from country of origin, and my rifle had to be made between 1946-1951 and that is good enough for me as I don’t think there is a way to know for sure the exact date.
Please disregard my last reply and thank you very much as I have learned more about my Enfield then I though I would and will pass this info along with my other WW II rifle to my son when the time is right.
Many thanks. Bob Greene
Hi Bob. No worries. Glad to help out. A final point concerning the location of the serial number letter. It was commonly placed above the number, but it is not unknown for the letter to be below the number or to either side of it.
Hi Barry, My Grandfather passed in January of this year with his last words to me being ” Cody you get first pick out of all my guns , now their are a few in there worth a lot.” Of course I told him “I don’t care about the guns! I won’t you!” Well, here I am! Anyways, my Great Grandfather on my Grandmothers side was in WWII and he has a M1. He is still alive and I am really big on history, also really really familiar with both of the great wars! One of the guns in the collection and one of his guns I have shot is a .303 British Enfield. I was so happy when I first held it two years ago 🙂 ! However, it is a very unusual looking Enfield? It has a whole different front sight than the one in the above pictures. Does not have the wooden shield on top of the barrel. It has the bullet drop adjustable rear sight. It only has a sling stud on the butt-stock, but not anywhere on the front of the rifle. It has horizontal grooves on each side of the foregrip of the stock. The bolt has a different serial # than the barrel and rear sight.
It has FI 131 on the bottom of the trigger guard.
Z stamped on the front of the drop-adjustable back-sight.
FI 35 or up side down right angle symbol then I 35 on the left side of the back-sight.
FI 45 at the very bottom inside when you lift the rear-sight all the way up.
FI 9 located just above the FI 45.
R located largely to the left of the FI 45.
E located largely under the serial # in the middle underneath the notched rear-sight.
FI 122 located on the base where the back-sight lays down on the barrel.
3 located just below the FI 122.
S C
HV located on the top of the barrel just behind the rear-sight.
FI 149 located on the left back side of the notch slider on the rear-sight.
3 located on the left front side of the notch slider on the rear-sight.
IG
H located on the very back left side of the barrel just in front of the action.
Crown
GRI
Crossed-Flags
P located behind the IG .
H
Same crest located just behind the previous crest stamp.
P located just to the right and on top the barrel from the crest stamp.
Serial # & E located twice next to each other on the right side of the barrel opposite from the two GRI stamps on the left side of the barrel.
Crossed-Flags stamped on the slide track of the bolt located on the front section of the bolt.
III stamped on the safety.
M located behind the action just to the right of the safety.
Scratched off crest on the top of the firing pin.
What looks like two A’s overlapping each other then a line underneath and the number 20 (stamped just to the right of the firing pin, but on the base plate underneath the bolt arm).
Bunch of worn down unreadable numbers and crest like shapes all over the bolt arm.
Crossed-Flags stamped on the back of the bolt arm just to the right of the non-matching serial #.
Crown
GRI
ISHAPORE
1940
SHTL .E Except the HT in (SHTL .E) has a line underneath those two letters.
III stamped on the right of the rifle just above the trigger.
S carved or stamped on the bottom of the hand grip of the butt-stock.
SZ
539 stamped or carved just below worn down unreadable letters on the right side of the butt-stock just in front of a Black Solid Dot.
BD-8699 stamped or carved on the left side of the butt-stock.
FI 167 stamped clearly on the inside of the cleaning kit cap on the back of the butt-stock.
L stamped on the top of the top front side of the magazine.
Magazine has two different non-matching serial #’s one ends with G and the other H.
The rifle is in good-shape for it’s age, and the action is very smooth like silk. Took it to the range today shot at a target 100 yards out. Aimed for center chest and it hit way up at the very top right corner of the paper with a grouping big enough to barely hit a basketball. Then I shot the rifle at the same target 50 yards out, and hit twice just above right shoulder while aiming center chest. However, the grouping of the two shots at 50 yards could cover a dime! That is extremely good grouping for the rifles age. My Grandmother told me that she thinks my Grandfather said one time that it was his Grandfathers, and my Grandfathers uncle Clyde served in WWII. I think that Clyde brought the gun back home from overseas and gave it to his brother George, My Great Grandfather on my Grandfathers side. Then George gave the rifle to his father, and when his father died it was passed back to George. Then when George died the rifle was passed back to Clyde who lived longer than George and his other brothers. Then when Clyde died the rifle was passed down the my Grandfather, and now me sadly. I really wanna know this rifle story!!!! It is very sentimental of value to me and so is the information on it’s history!
I have pictures of the gun if you want me to email them to you or something? I really hope you can help me ASAP with this? I would also like to know what scope mounts and rings I need to put a scope on the rifle. Also how I would put a Bi-pod on as well as a sling.
Thanks.
With apologies, I’m going to have to cherry-pick from the big batch of markings that you list. Perhaps other more knowledgeable commenters will fill in the gaps and correct my mistakes. Let’s start with the obvious – the action body was manufactured in 1940 at Ishapore, north of Calcutta. The barrel also came from there and is original to the action body if the serial #s match. The G and H non-matching serial #s on the magazine are among those found on weapons made by Ishapore between 1940-45. Barrel markings show that the finished weapon was proofed by Ishapore. The SC (small cone) and HV (high velocity) on the barrel indicate that the small or forcing cone of the barrel is 0.02 inches deeper than earlier production barrels to accommodate the Mk VII cartridge (introduced in 1911), which had a pointed bullet. The H on that barrel also makes me wonder if it may be a “heavy” of the type that the Australians cranked out for use as sniper rifles. If so, it’s news to me that similar barrels were coming out of Ishapore.
In my humble opinion the enfield bolt action rifle is a precision weapon if properly maintained and equipped with good sights , either iron aperture sights or optical telescopic sights. Terrorists are usually not particular about whom they are killing, and can thus use assault rifles to spray bullets on crowds .
The law enforcement personnel responding to such attacks must use precision weapons to target the terrorist alone, when he is surrounded by people .They cannot fire indiscriminately, killing innocent bystanders.
As mentioned above, the police personnel are probably not trained in marksmanship ,and the weapons are poorly maintained, generally carried around for show . The answer is to improve maintenance and accuracy of the existing weapons, and to improve training in marksmanship , so that the pathetic performance of the police during the 2008 attacks is not repeated.
The British Army was using accurized enfield bolt action rifles for sniping till the 1980’s. The US army and marines still use bolt action rifles for precision work, such as sniping and SWAT operations.
Excellent comment. As for the enduring utility of the Lee-Enfield, I like George MacDonald Fraser’s comment on the outriders of a caravan arriving at a North African village: “What the wild men of the world will do when the last Lee Enfield wears out, I can’t imagine; clumsy and old-fashioned it may be, but it will go on shooting straight when all the repeaters are rusty and forgotten” (The Complete McAuslan 2009, p. 203).
Hi dear Barry
I have a SMLE MKIII* Ishapore made . I wonder what the letter “R” on the right side of the bolt head and the rear sight guard stands for . I don’t know the meaning . By the way the rifle made in 1943 . Thanks in advance for your help
Like you, I find many of the single letter markings on these weapons are tough to interpret accurately. I have a MkIII bolt head on my desk with an “M” stamped in the center of its side, but no other markings. To the best of my knowledge the “M” simply means the bolt head was made of malleable cast iron. If your “R” is in a similar place, then it too may reference the bolt head material. Alternatively, the “R” on the bolt head and the rear sight guard of your weapon may be armourer markings identifying replacement components. I’ll throw these speculations out here and see if a more knowledgeable reader wants to enlighten us both.
I have an Ishapore ShtLE No.1 Mk 3 dated 1916 with the mag cutoff and the ser# is 1547(no letter prefix). I was just wondering what the date of manufacture might be.
Thanks in adcvance for any help,
AD
Your rifle was made early during the 1916 production year. Ishapore cranked out nearly 140,000 Mk III/Mk III* between 1914-18. According to Stratton (2009)”SMLE(No. 1) Rifles, Mk 1 and Mk III”, p. 125, Ishapore’s serial numbers in 1916 either had no prefix or the letter “A”.
Dear Sir,
Hope you can assist, the marking are from top to bottom,
GIR
ISHAPORE
9417
SHILE
III *(star)
and another marking
1022
As I have read previous discussions that some times the marking is wrong when they are marked. Any idea as too when this gun was made or any other info you can ascertain from the given info from me. Thanks
Many thanks.
HS
Readers: If you are familiar with action body markings, then Harpreet’s recent query may leave you scratching your head. The markings simply make no sense, I said in my initial response to HS and I asked him for a photo, which I share below. Check it out. Each line of the markings is full of mistakes, big and small, that one would never see on a real Ishapore rifle. I believe it is an example of a weapon type called a “Khyber Pass Special”, a copy of a factory original made by hand by a small shop or village gunsmith.
For a brief introduction to Khyber Pass Specials, read https://en.wikipedia.org/wiki/Khyber_Pass_copy
Harpreet: Many thanks for sharing information about this excellent example of a very interesting rifle.
Barry
I am very glad you brought up the Khyber Pass guns. I bought a jungle carbine about 20 years ago. It really confused me, though the gun was a little rough in places it shot straight and was fun to shoot. That is tell I broke an extractor, I bought a spare bolt and it would not fit the gun. This left me scratching my head. Then I saw an Article about Khyber Pass Jungle carbines with photos. I sent the author of that article pictures of my weapon, and told him where he bought his.(lol) We had purchased them from the same place. This makes my weapon even the more interesting to think somebody with a file on a dirt floor built this thing a total one off. no wonder parts didn’t fit. Those guys at Khyber write anything on the side they want to write to try and make them look official. I kept my gun and use it for a great story it’s a pretty cool curio. It was sure fun to shoot while it lasted. Maybe I am lucky to still have my arms.
Hello I recently purchased an ishspor smoke dated for 1987 chambered is 303. The parts are all matching. Was this the last year of production for 303? Why did India make rifles in 303 and 308 for the 2A version?
To the best of my knowledge, there wasn’t a 1980s production year for .303s at Ishapore. In his book on the Lee-Enfield, Skennerton (2007:371) mentions that recent surplus shipments of Ishapore 2A and 2A1 rifles to the US included “.303 rifles with manufacture years in the late 1980’s, although the quality of finish is certainly not as good as earlier production. These later dated rifles may even have been made elsewhere, such as on the North-West Frontier, despite their Ishapore markings.”
Just picked up another .303 Enfield, I know little about, I’ve a .303 Enfield Savage built Lend/Lease, Sav has a rear sight, the Ishapore and is on receiver. Has a 1944 stamped and F.R. Which I read I’d factory repair . When was the sight moved to receiver ?
Thanks
Given that it is a Savage weapon, I’m guessing that your new rifle is one of the No. 4 Mk I weapons built by their J. Steven Arms division. Their total for the No. 4 was a little more than 1 million rifles before production ended on 30 Jun 1944.
As for the sight, British production began testing an aperture sight as early as the beginning of WWI but they did not reach a firm decision very quickly. Versions of the rear sight and its placement are found on the No. III Mk V and Mk VI, the latter of which became the No. 4 Mk I in the early 1930s.
Hello. I know of an Ishapore .303 rifle with a stamp on the butt stock, it is a circle with a broad arrow and TDE (W). Any idea what part of the Commonwealth that is?
The roundel is a post-1951 Indian arsenal mark. According to Robert Edwards (“India’s Enfields” 2003, p. 62), “By 1943 the familiar ’roundel’ containing the letters ISA, used since 1917” was replaced by the letters “SIA surmounted by a broad arrow in a roundel”. After 1951, SIA was dropped in favor of the letters TDE.