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Alpine Railway


Communications link - Rolling Stock Reference - Swiss Crocodiles            

Welcome to the Crocodiles Theme Page!

 Background for the need of Crocodiles
The Gotthard route in Switzerland had to be electrified in a hurry since Switzerland did not get anymore coal from the neighbouring countries during World War I. Due to this emergency the plan to test first the electrical traction between Bern and Thun with some prototypes before ordering series locomotives could not be realised. Therefore the series locomotives had to be ordered before testing of the prototypes was done.  The ordered series were
Be 4/6 12303 - 12312, Be 4/7 12501 - 12506 and Ce 6/8 II 14251 - 14260.
While the mechanical part was delivered for all locomotives from SLM, the electrical part was shared amongst the three Swiss manufacturers of electric equipment. The electrical part of Be 4/6 was from BBC, Be 4/7 was from Secheron (SAAS) and Ce 6/8 II was from MFO.  
 Ce 6/8 I  0 series 
SBB ordered a first unit for this new type of locomotive in 1917. It was
supposed to be of type Ce 6/6 (C= top speed 60-65 km/h, e= electric, 6/6
means six driving axles out of six total) and based on Be 4/6. With common
components less spare parts were needed. In order to fit all equipment
needed and distributed the weight properly the locomotive had to be extended
with one trailing axle in both ends. Because of these funny suitcase-like
boxes the locomotive was called Köfferlilok (Köfferli = small suitcase).
With the trailing axles the locomotive was named Ce 6/8 14201, renumbered
to 14201, later repainted from the original brown to green. This prototype was built by the manufacturers SLM (Schweizerische Lokomotiv- und
Maschinenfabrik) for the mechanical part, and BBC (Brown, Boveri & Cie.) for the electrical part and final assembly. With is 1750kW (2350 Hp) it was a very strong engine in its time and even slightly more powerful than the Ce 6/8 II. Only one prototype was made, but it was in service until 1982 and is now stored in the depot at Erstfeld as a historic locomotive.  
SBB Crocodile ce6/8 1 from Switzerland        

The first series, Ce 6/8 II    
SBB Crocodile ce6-8 II from Erstfeld Switzerland
These real Crocodiles were made between 1919 - 1922 and went straight on to take over practically all freight traffic on the Gotthard route. With their top speed of 65 km/h (41 mph)  and power rating of 1650kW (2210 Hp) they managed to pull 430t at 35 km/h (22 mph) up the 2,6% gradients, an astonishing accomplishment at that time! Compare this with the 600t at 100 km/h (62 mph) nowadays. The Ce 6/8 II 14251-14283 was delivered in brown livery and single-contact-shoe pantographs, thus they needed to have both pantographs raised for optimal power collection. With these 33 machines the name crocodile came into use. With the proportionally short cab in the middle and long, low and bendy noses in both directions they really resembled crocodiles crawling through the landscape. Since side rod drives of the two halves are working independently which made the crocodile rock slightly, the engineers also called it "Berceuse", "the rocking chair".      
SBB Crocodile ce6-8 II number 14270 from Erstfeld Switzerland

The second series, Ce 6/8 III
As the traffic continued to grow there weren't enough crocodiles, a problem
easily coped with by ordering more of them. With all the experience gained
from the already used crocodiles only a few things had to be changed when
building the Ce 6/8 III. The easiest way to distinguish between II and III is by looking at its wheel arrangement or more closely at the driving rods. In both series they used a layshaft for power transmission. The difference comes after that: in II the power is transferred by a triangle rod to the first driving axles with a jackshaft in front of the first axle whereas in III the power is straight pushed on the three driving axles with the so called Winterthur diagonal rod. The prototype Ce 6/8 I used a mirrored version of the latter. The Ce 6/8 III were numbered 14301 - 14318 and delivered 1924 - 1927 with slightly more power, 1810kW. Thus they could take slightly more load, but had the same top speed.
The crocodiles handled all the heavy freight over Gotthard for many years
without problems. In the 1940s the constant full utilization was starting to show signs of usage on the crocodiles. With no good replacement in sight a program to upgrade parts of the fleet was started. Starting in 1941 13 of the Ce 6/8 II
were upgraded with newer traction motors giving 2700kW (3620kW) . This enabled the 13 upgraded crocodiles to run at 75 km/h (46 Mph), which in turn led to renaming them to Be 6/8 II (B stands for a top speed of 70 to 80 km/h) and renumbering them to 13251 - 13265. As they were upgraded they were painted green; the engines that  weren't part the upgrade got the green paint during normal service. Now they looked even more like crocodiles!
All of the Ce 6/8 III were also painted green, named Be 6/8 III and renumbered 13301 - 13318 in the 1950s. The Ce 6/8 III had from the beginning more powerful motors which could pull the trains at 75 km/h
(46 Mph).
New times
New engines emerged with new technology and the crocodiles started to be 
too slow with only 75 km/h top speed. 1954 the new faster and more powerful Ae 6/6 (A for top speed exceeding 80 km/h) started to replace the crocodiles on the Gotthard route. The crocodiles were pushed to flatter regions where they continued to pull freight with great success. Due to wear and tear caused partly by the speed and power upgrade some cracks started to emerge in the frames around the couplings and the engines had to be restricted to 65 km/h
(40 Mph).
Ce 6/8 II 14274 - 14283 were later rebuilt as heavy switchers, a perfect task
for a very strong but slow engine. These engines got platforms for the crew
and better hand rails.
Nowadays all crocodiles are withdrawn from revenue service, but there are 7 preserved Ce 6/8 IIs and 3 preserved Be 6/8 IIIs. Some of them are in working condition and some are also outside of Switzerland.


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Created for by Andreas Ehnberg, Peter Christener and John McKey. Pictures by Ilkka Siissalo, Stanislav Voronin and John McKey.

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© Railroad Reference 2004 - 2010  -  Created 21.8.2009 Andreas Ehnberg,  Updated 27.1.2010 Peter Christener