SLIDING Gas-Hydraulic Buffers

High-technology shock absorbers combined with friction breaking technology. Its performance is unique for this type of equipment. They stop trains and maintenance vehicles avoiding serious damages to the passengers, rolling stock and track infrastructure. They allow micro-impacts without any further intervention and control deceleration to the desired value.

Llalco supplies high technology energy absorbers and unique features in these equipment, tailored to give the best solution to our customers. We work with hydraulic gas shock absorbers consisting of two chambers: one of nitrogen gas and another of oil, which act by means of a sophisticated damping mechanism constituting a gas-hydraulic shock absorber.

Sliding Buffers. Adapted solutions for each project. Examples:

LL-9-D-D Buffer Stop:
optimal for metro and tram systems, with front end adapted to the central coupling of the train.

LL-2-9-D-D Buffer Stop:
suitable for freight and AVE trains, with multi-purpose front end adapted to the central coupling of the train and side buffers.

LL-9-D-D-C Buffer Stop:
with maximum C5-H corrosion protection for areas of high humidity and salinity.

LL-712-D-D Buffer Stop:
high performance on test tracks, with high performance capsule for higher speed impacts.


They are 99% efficient, i.e. 99% of the energy produced by the impact is absorbed by the Llalco capsule. This has been confirmed in tests conducted by European railway companies.

Constant comfort deceleration

As regards deceleration, we should explain that it is not sufficient just to stop the train after an impact; the best way is to do so by means of a predetermined and constant deceleration from the beginning of the impact until the train has come to a complete standstill, without producing recoils that would have fatal effects for passengers and cause material damage. Llalco achieves this by enabling a deceleration that is comfortable for passengers and safe for the integrity of the train, using a system that retracts the buffer at a constant, previously calculated speed.


Llalco-pneumatic buffers do not require any regular maintenance, since only one part of the mechanism moves when they act. As a result of this, their performance remains exactly as calculated for more than fifteen years, after which time the gaskets can simply be changed and the unit will continue to be operational.


Our buffers meet the highest quality standards and correlate with the unique combination of our shock energy management simulator.


Our shock absorbers are completely cost-effective, as they drastically reduce the cost of maintaining and repairing the rolling stock, as our clients can confirm (below you will find a reference to the Spanish organisations that have put their trust in this system), since impacts against the buffer stop or between carriages are absorbed, within the speed range for which they were designed, with the same smoothness and efficiency, thus avoiding potential damage and/or discrepancies due to costly repairs.


Our equipment is approved and/or standardised by the railway companies of every country (see the non-exhaustive list in the general catalogue), showing through their confidence that Llalco is cost-effective for them.
Cuatro Vientos - Metro de Madrid

reference gallery

ARE YOU INTERESTED IN ANY OF OUR Gas-Hydraulic Sliding Buffers?

Fill in the form to speed up the process and receive your offer sooner

    I have read and accept the legal terms and the privacy policy.

    • Responsable:Llalco Fluid Technology, S.L.
    • Dirección del Responsable: C/ Natalia de Silva, 3 – 28027 Madrid
    • Finalidad: Atender la petición realizada por el interesado a través del formulario.
    • Legitimación: Trataremos sus datos cuando nos preste su consentimiento mediante la marcación de la casilla correspondiente.
    • Destinatarios:Los datos no serán comunicados a terceros salvo obligación legal.
    • Derechos: Acceso, rectificación, supresión, oposición y otros derechos detallados en la información adicional.
    • Información adicional: puede ampliar esta información en la Política de Privacidad de nuestra página web.