Ariane 5 SRBs: Monolithic or Segmented?

[Proponent]

Are Ariane 5's solid boosters monolithic units or do they consist of segments as do the Shuttle's SRBs?  If monolithic, how are they transported to French Guiana and from where?

[Stephan]

Three segment per booster IIRC, they are built (at least filled) in Guyane.

[Nicolas PILLET]

Three segments, as said Stephan, S1, S2 and S3.

S1 is made in Italy. S2 and S3 are made in CSG.

[Proponent]

Three segments, as said Stephan, S1, S2 and S3.

S1 is made in Italy. S2 and S3 are made in CSG.

How do the segments differ from one another?  I'm surprised that they're manufactured in different places.

[spacejulien]

Three segments, as said Stephan, S1, S2 and S3.

S1 is made in Italy. S2 and S3 are made in CSG.

The S1 segment is the short one on top of the booster, it's the starter segment also carrying the igniter. It's manufactured in Germany (near Munich) and filled with the propellant in Italy (near Rome), then it's transported to Kourou. The other two large segments S2 and S3 are also produced in Germany but transported to Kourou directly and filled there.

The igniter segment (S1) has a more complex shape of the propellant inside, thus the decision has been made to cast it in Europe, whereas the big segments would weigh more than 100 metric tons each, if filled. That and additional security issued led to the decision to fill them in Kourou.

The large segments casings are made of three cylinder parts each and assembled (welded) on site in Germany.

~spacejulien