Antivibration technology
Vibration isolation for the world’s steepest two-cabin funicular railway A world record is in the making in the heart of Switzerland:
a new two-cabin funicular railway with a maximum gradient of 110%
is being built from Schwyz to Stoos. This technological innovation requires
a mighty 1,360-horsepower drive motor positioned in the summit station.
And to keep the motor’s vibrations from getting transmitted to the station
building and its enclosed office quarters, a perfectly frequency-calibrated
and easy to install solution was required.
There is something to see up here at 1,305
meters – now more than ever: Far below the
beautiful mountain village of Stoos, home to
150 permanent residents who can access
their village only by railway or foot, lays
Lake Lucerne that glitters on clear days. The
rocky peaks of the Grosser Mythen and
Kleiner Mythen soar up in the opposite
direction. Now let’s add some technology
to this majestic natural scenery: In spring
2014, Stoosbahnen AG, the company that
operates the transportation infrastructure to
Stoos, opened four observation platforms
from which the spectacular construction site
for the new funicular railway can be viewed.
When completed according to plan, from
2016 onward the new 1,758-meter-long
funicular railway will overcome an altitude
difference of 744 meters.
To be able to transport up to 136 people
and six tons of cargo in three to five min­
utes, the new railway relies on a drive motor
that is capable of delivering short-term peak
surges to up to double its rated power output
(2 x 1,000 kW). The motor emits its strongest
vibrations during the time it takes to reach its
full engine speed, and those vibrations must
not be transmitted to the fragile surrounding
alpine environment. Armin Ziegler, who with
his Ziegler Consultants engineering firm
specializes in vibration isolation for the con­
struction industry, therefore recommended a
tuning frequency of 15 Hz for the foundation
bedding.
Imposing technology set against the impressive
mountain scenery of the Grosser and Kleiner
Mythen: construction of the new Stoosbahn.
APSOPUR® damping mats will absorb the
vibrations of the drive motor at the mountain
railway station.
APSOPUR® damping mats in standard formats on the floor and sidewalls. They were covered in plastic foil prior to reinforcement.
Using standard material to create a custom- How it’s done ”With APSOPUR ® we obtain
ized solution ”We met the 15 Hz specifica­ an optimal tuning frequency and can ab­
tion through an optimal choice of material
sorb almost all of the vibrations of the drive
motor, particularly in the start phase when
from our APSOPUR ® product range. The
foamed polyurethane mats selected uni­ it is revving up to full speed. At the same
formly compress 2.5
time, the mat tiles made
to 3 millimeters,” says
of foamed polyurethane
Andreas Ferrari, pick­
are easy to install,” An­
After appropriate training,
ing up the thread. He
dreas Ferrari explains.
the construction company
heads Angst + Pfister’s
The exemplary work
Antivibration Technol­ is able to install the isolation
steps in Stoos pro­
ogy product group in
ceeded as follows: The
elements independently
Zurich. The antivibration
1 × 1.5 m standard-sized
and in-house.
field engineers in his
mat tiles were laid di­
rectly adjacent to one
team worked very close­
ly on this assignment with the Slongo Röthlin
another and fastened together using off-thePartner AG, the responsible engineering firm
shelf adhesive tape. To completely cover the
in Stans. Their calculations took account of
concrete foundation, the mat tiles were man­
ually cut to size where needed. The leftover
the fact that the foundation slab during the
pieces could also be utilized. Afterwards
12-month construction phase would have to
the side walls were likewise clad with
bear a load of 5.5 t/m², which is almost twice
APSOPUR ®. The mat tiles were bonded di­
the continuous static load of 3.9 t/m² that it
will bear once the construction is completed. rectly to the wall, and edges and seams were
The choice of material was based on stan- additionally taped. A second APSOPUR ®
dard grades and thicknesses: part of the con­ layer was laid on top of that, not laterally like
crete foundation is bedded on APSOPUR ®
the first one, but instead lengthwise so that
type H11 mats, which are capable of absorb­ the mat tile seams did not lie on top of each
ing a static load of 0.11 N/mm²; the other
other. A plastic sheet then covered the iso­
part is bedded on APSOPUR ® type L55 mats, lation, for safety reasons to ensure that po­
which can handle a load of 0.055 N/mm². tential slag during the later concrete-pouring
stage could not form any sound bridges.
Once the isolation had been examined by an
2
1
2.50
3
3.83
3.83
Vibration isolation – a job for construction pros ”Any construction firm that works
carefully and correctly is capable of carry­
ing out these steps on its own,” Mr. Ferrari
says. ”We at Angst + Pfister are glad to drop
by to brief the workers on the installation
instructions. Afterwards they can lay the
isolation layer or layers themselves and the
construction firm can get the work done
independently.” He points out the excellent
reliability of APSOPUR ® products and solu­
tions – ”and we planners take responsibility
for the calculations.”
Foreman Philipp Lüönd, who supervises
the summit-station jobsite in Stoos for the
construction firm Bolfing AG, also confirms
that this division of responsibilities stands the
test: ”We felt well supported by Angst + Pfister,
so we were able to build the floating floor
for the vibration isolation ourselves with
a secure feeling and a secure hand.” The
new funicular railway up to the Stoos moun­
tain village will incorporate sophisticated,
well-engineered technology right down to
the summit station’s foundation.
4
5
3.82
4.80
6
4.20
7
8
4.20
9
4.20
5.40
5.16
36.78
25
Fixpunkt Bergstation
3
+5.30
+5.05
40
4.00
Bereich Vordach
3.80
3.20
±0.00
Bereich Tore Güter / Gepäck
±0.00 = 1'306.10 m ü.M.
neue SOK
5.05
3.80
3.30
Güter / Gepäck Terminal
Bereich Fahrgäste
5.05
Standseilbahnhof
Treppe mit
Dilatation
Bereich Güterumschlagzone
72
7
3
22
+5.05
7.00
-3.20
NL Gitterrost:
generell 1 kN/m 2
lokal 5 kN/m 2
50
Maschinen- und Antriebsraum
-5.30
20
16.31
4
4
-7.60
-7.64
25 4 60
-7.00
80
30
5.71
Metr. km 1'547.256 (Situation)
Metr. km 1'780.687 (Abwicklung)
693'510.700 / 203'723.960
28.88
2
The mountain railway station
with cylindrical cabins, drive
and antivibration isolation
(in red).
expert, the reinforcement could be installed.
Afterwards, in line with the standard proce­
dure, the antivibration engineer’s scrutiniz­
ing eye was needed once again. Only then
was the concrete poured over the isolation
– and the floating floor was finished.
3
2