TB BFrom 4/8 - BOB ABDeh 8/8
|TB/AB BDe 4/8 21–25, SAD 21–24|
BDe 4/8 22 of the Trogenerbahn near St. Gallen Notkersegg
|Manufacturer:||FFA , SWP , BBC|
|Year of construction (s):|| Nr. 21–23: 1975 |
Nr. 24, 25: 1977
|Ausmusterung:||No. 22: 2008|
|Axis formula :||B0'B0' + 2'2'|
|Genre :||for TB / AB: BDe 4/8|
|Gauge :||1000 mm (Meterspur)|
|Length over coupling:||30 200 mm|
|Total wheelbase:||24 800 mm|
|Service mass:||40 t|
|Top speed:||65 km / h|
|Hourly output :||400 kW (544 PS )|
|Power system :||600-1000 V =|
|Number of traction motors:||4|
|Seats:||66 + 6 folding seats|
|Classes :||2nd Class|
|Loading area:||5,5 m²|
The BDe 4/8 21-25 were meter-gauge four - axle electric multiple units with a second class and a baggage compartment, which were put into operation by the Trogenerbahn (TB) in 1975 and 1977 . In 2006 they became part of the Appenzeller Bahnen (AB) portfolio through the merger of TB . In 2009 the BDe 4/8 21 and 24 came to the Rittner Bahn in South Tyrol, in 2014 and 2017 the BDe 4/8 23 and 24 followed.
After the federal government and the cantons of St. Gallen and Appenzell Ausserrhoden approved the financing, the Trogenerbahn was able to order the BDe 4/8 21–23. The three multiple units arrived in Speicher in autumn 1975 and were inaugurated on November 28th.
With a further order, three identical multiple units should be purchased. Because the Federal Office of Transport (EAV) used the prices of the first order instead of the current offer, the credit was only sufficient for the two BDe 4/8 24-25. Instead of the third multiple unit, the BDe 4/4 6–8 were modernized. The five multiple units took over the main load of the traffic and enabled the sale of the BDe 4/4 3–5 as well as the release of one BDe 4/4 6–8 each for the renovation work.
After the delivery of the Be 4/8 31-35 , part of the Be 4/8 at the Appenzeller Bahnen, to which the Trogenerbahn has belonged since 2006, became redundant. The multiple unit 25 was scrapped in May 2008 and then scrapped.  The remaining nos. 22 and 23 served as a reserve until the Tango trains ABe 8/12 were acquired. 
Technical description, changes
The multiple units consist of a railcar and a control car that are firmly connected to each other. The car body is made of steel in order to obtain a sufficiently large adhesion weight . The control car, however, is an integral aluminum construction to save weight . The bogies are equipped with SAB rubber-sprung wheels . The four-leaf folding doors with folding steps were operated electro-pneumatically. The vehicles have a sand spreading device , flange lubrication and train radio . The multiple controlallows up to three multiple units to be operated together. Many parts of the electrical and pneumatic equipment are identical to the BDe 8/8 of the Bremgarten-Dietikon-Bahn (BD). 
From 1982 the traction motor feed lines had to be replaced and corrosion damage repaired. In 1984/85, illuminated roller tape displays were installed on the fronts and in 1988 stop announcement devices. In 1992 the TB replaced the double folding doors with double-leaf revolving doors. From 2001 to 2003 the baggage compartments were converted into a multi-purpose compartment accessible to passengers by moving the partition.
The sale of the BDe 4/8 21 and 24 to the Rittner Bahn belonging to the South Tyrolean transport structures and operated by SAD came about on a private initiative . Because there was asbestos in the roof area, renovation was carried out before export.  On the night of April 28, 2009, the two multiple units were transported to Klobenstein am Ritten .  Because the new feeder cable car led to an increase in traffic, the Rittnerbahn needed the multiple units from Appenzellerland to introduce the half-hourly service. After the necessary adjustment work, multiple unit No. 24 was put into operation in May 2010. No. 21 followed in September 2010. The Rittnerbahn was able to take over some spare parts of the broken off BDe 8/8 from the Bremgarten-Dietikon-Bahn .  First, the multiple units ran on the Rittner Bahn in the orange VST livery . Shortly after the takeover, they were given a dark gray paint job and wine-red driver's cabs, and at the same time the direction indicators that were no longer needed were removed.
After the annual passenger numbers of the Rittner Bahn rose from 250,000 to more than 500,000, the BDe 4/8 23 was taken over in November 2015.  On November 13, 2017, the 22 was the fourth and last multiple unit to be transported to South Tyrol, after it had previously gone through an asbestos removal in the Speicher depot. 
- Jürg Aeschlimann, Hans Waldburger: St. Gallen – Speicher – Trogen tram; The Trogenerbahn . Prellbock Druck & Verlag, Leissigen 2003, ISBN 3-907579-24-0
- Heitersberg: AB BDe 4/8. On: www.juergs.ch, February 2018
- Jürg D. Lüthard, Mathias Rellstab: From Trogen to South Tyrol. In: Swiss Railway Review . No. 5/2009. Minirex, , p. 252
- Helmut Petrovitsch, Jürg D. Lüthard: Trogener railcar on the Rittnerbahn in plan use. In: Swiss Railway Review. No. 7/2010, p. 363
- Helmut Petrovitsch: BDe 4/8 arrived in South Tyrol. In: Swiss Railway Review. No. 6/2009, p. 311
- E. Sutter: Trogener trains on the Renon. In: Swiss Railway Review. No. 8-9 / 2009, p. 420
- Jürg D. Lüthard: Third TB railcar in South Tyrol. In: Swiss Railway Review. No. 1/2015 p. 11
- D. Widmer: Last TB train to South Tyrol. In: Swiss Railway Review. No. 1/2018, p. 9