RENFE Fleet Numbering

[sulzer27jd]

In the Spanish fleet numbering system, what does the final (7th) digit signify? 

 

For example 319.237.4 - What does the 4 mean?

 

Thanks

 

John

[D9020 Nimbus]

It's probably a "check digit" — one calculated from the others so computer systems can check whether the correct number has been entered — they're used in Germany (DB) but not everywhere (not UK or France, for example — unless things have changed). They've been used in Germany since about 1968 (“era IV”).

[Bill Jamieson]

It might just be a coincidence, but applying the DB way of calculating the check digit works in this case - multiply the digits of the loco number alternately by 1 and 2, sum the resultant digits and subtract from the next multiple of ten above - 3+2+9+4+3+1+4=26: 30-26=4

 

Bill

 

PS I did a bit of photography of what little steam was left on the Portuguese metre-gauge in the mid 1980s, by which time the locos were carrying computer numbers (and the nice brass chimney-mounted plates had been removed). For example 2-4-6-0T Mallet E202 on the Sabor line carried the number 3 079 202-0, but I've never been able to work out the derivation of the check digit - if anybody out there knows the answer I would be very interested to hear it!

Edited August 13, 2020 by Bill Jamieson

[Fat Controller]

56 minutes ago, Bill Jamieson said:

It might just be a coincidence, but applying the DB way of calculating the check digit works in this case - multiply the digits of the loco number alternately by 1 and 2, sum the resultant digits and subtract from the next multiple of ten above - 3+2+9+4+3+1+4=26: 30-26=4

 

Bill

 

PS I did a bit of photography of what little steam was left on the Portuguese metre-gauge in the mid 1980s, by which time the locos were carrying computer numbers (and the nice brass chimney-mounted plates had been removed). For example 2-4-6-0T Mallet E202 on the Sabor line carried the number 3 079 202-0, but I've never been able to work out the derivation of the check digit - if anybody out there knows the answer I would be very interested to hear it!

The number, and check-digit, are calculated according to a UIC standard. It has been used for freight and hauled passenger stock for at least a couple of decades, being extended more recently to locomotives and multiple units.

[Bill Jamieson]

 

12 hours ago, Fat Controller said:

The number, and check-digit, are calculated according to a UIC standard. It has been used for freight and hauled passenger stock for at least a couple of decades, being extended more recently to locomotives and multiple units.

The UIC numbering system appears to have been applied to locos from 2007. In Germany and Austria (the European countries with which I'm most familiar) the full numbers are only applied to loco body-sides and.the change certainly didn't affect the check digit which is still calculated from the national number only (ie it ignores the type and country codes). In fact in Germany the first digit of the supposedly four digit class number is also ignored and the check digit calculated from the old style three digit class and running numbers using the method I explained earlier eg 185 190-6 (1+1+6+5+2+9+0 = 24-30 = -6). Incidentally this appears to be known as the Luhn algorithm but it certainly doesn't work with the Portuguese metre-gauge locos and I was hoping someone might clarify what method the CP used back in the 1980s.

Bill

Edited August 14, 2020 by Bill Jamieson

[EddieB]

On 13/08/2020 at 21:34, Bill Jamieson said:

PS I did a bit of photography of what little steam was left on the Portuguese metre-gauge in the mid 1980s, by which time the locos were carrying computer numbers (and the nice brass chimney-mounted plates had been removed). For example 2-4-6-0T Mallet E202 on the Sabor line carried the number 3 079 202-0, but I've never been able to work out the derivation of the check digit - if anybody out there knows the answer I would be very interested to hear it!

The check digit applied when CP adopted the UIC numbering system is the international standard (Luhn algorithm).  The discrepancy with E202 is that the number reported wasn’t the full 11+1 digit UIC number.  The full number should be 90-94 3 079 202-0.  Putting the first eleven digits into my check digit calculator confirms that the check digit should be zero.

[EddieB]

On 14/08/2020 at 07:43, Bill Jamieson said:

 

The UIC numbering system appears to have been applied to locos from 2007. In Germany and Austria (the European countries with which I'm most familiar) the full numbers are only applied to loco body-sides and.the change certainly didn't affect the check digit which is still calculated from the national number only (ie it ignores the type and country codes). In fact in Germany the first digit of the supposedly four digit class number is also ignored and the check digit calculated from the old style three digit class and running numbers using the method I explained earlier eg 185 190-6 (1+1+6+5+2+9+0 = 24-30 = -6). 

The transition to full UIC numbering in Germany and Austria is a little more complex than first appears.

 

For German electric locos, the "UIC prefix" (first five digits) are "91 80 6", whose effect is cancelled out in the check digit calculation.  Taking your example, both "91 80 6 185 190" and "185 190" obtain the same check digit.  As a result many (most? - but not all) German electrics show the check digit with both long and short form numbers.

 

The situation for German diesel locos is different, where the "UIC prefix" of "92 80 1" results in a different check digit.  A similar situation applies to multiple units.  From what I can tell, the check digit is omitted where the short form number appears on the front of a locomotive.

 

Austria has been slower to apply UIC numbering, which may be explained by a similar discrepancy between the "old" and "new" (UIC) check digits.  Due to the coding used, the discrepancy affects both electric and diesel locos.  Here's a real example (from Selzthal, July 2018).

The full UIC number "92 81 2070 008" results in a check digit of "5", which has been applied where the full UIC number is given on the cab side.  The original short form number "2070 008" results in a check digit "4" - as appears on the front of the locomotive, but where an attempt has been made to paint it out.  This appears to be standard Austrian practice.

 

In danger of over-generalising the same pattern seems to apply in other countries, namely to omit or paint out a check digit from the displayed short number, where it would differ from the full UIC calculation.  Where the two calculations coincide, then check digits are displayed with both forms.

 

To illustrate that point, here's another "happy coincidence" where both the full UIC number and the short form result in the same check digit calculation  (Komárom, August 2018), so both numbers are given with the check digit.

 

 

[Bill Jamieson]

On 16/08/2020 at 13:42, EddieB said:

The check digit applied when CP adopted the UIC numbering system is the international standard (Luhn algorithm).  The discrepancy with E202 is that the number reported wasn’t the full 11+1 digit UIC number.  The full number should be 90-94 3 079 202-0.  Putting the first eleven digits into my check digit calculator confirms that the check digit should be zero.

Thanks Eddie that seems to have solved the puzzle, although I reckon that the individual digits need to be multiplied by 2 and 1 alternately (ie starting with 2 rather than 1) to get the correct check digit. I've tried E202 and also E144 (a Henschel 2-8-2T now preserved) which latterly carried 3 079 144-4 (the 90 94 type and country codes were never carried by CP metre-gauge steam locos to my knowledge).

You're quite correct about OeBB locos but it appears that the old and new check digits on DB diesel locos should also be the same - that's something I hadn't appreciated before. Applying the Luhn algorithm to the digits 9280 1 (but multiplying alternately by 2 and 1) gives a sum of 20 which leaves the check digit based on the old 2xx xxx number unchanged. Recent photos of diesel locos on the German Fotocommunity site show the check digit still applied to the front of the loco eg 218 456-2 and 232 690-8. 

Bill

PS The upshot of this is that while I was incorrect in suggesting that the check digit wasn't calculable from the 11 digit UIC number, the reality is that for DB locos and dmu/emu vehicles the check digit is derived from the xxx xxx number and a one off fudge to the four digit class numbers (as reported to the UIC but presumably never used within Germany for day to day purposes) ensures that the whole 11 digit number gives the same check digit as the DB six digit one. I wonder if this applies to other railway administrations using six digit numbers.

 

Edited August 18, 2020 by Bill Jamieson