Hard as beech

Robust and durable beech sleepers and turnout sleepers are an alternative to those made of oak. With serious market shortages of the latter material, beech sleepers are now a desirable and economically justified solution for railway investment contractors.

Wooden sleepers are still an important component of the railway surface. Their advantages are known – they damp vibrations very well, do not conduct electricity, have little susceptibility to temperature changes, better tolerate a weaker subgrade and are also lighter and cheaper than pre-stressed pretensioned concrete sleepers. “This is why this technology is still widely used in the railway industry. Nasycalnia Podkładów in Czeremcha is the only company in Poland that uses 100% type “C” creosote oil, which helps new wooden sleepers from Czeremcha be less burdensome on people and the environment.” says Ryszard Sokołowski, CEO of Nasycalnia Podkładów in Czeremcha, a company within the KZN Bieżanów Group. The wooden sleepers, turnout sleepers and bridge sleepers are an indispensable component of both maintenance and revitalization works, as well as for the implementation of modernization processes related to the National Railway Program. In addition, the vast majority of industrial sidings use wood as a part of the track surface. The demand for wooden products is still significant. Due to their higher durability, hardwood sleepers have of late been ordered more frequently. When talking about hardwood, the majority of customers understands this only as elements made of oak. Nevertheless, according to Polish standards and TSI standards, they can also be made of exotic azobe wood and beech. And if African wood on the railway is rather a historic niche, then beech sleepers are a very good alternative to those made of oak.

“In 2016, in order to confirm this material’s very high operating parameters, the Railway Institute carried out a series of tests.” says Sokołowski. “The flexural strength of beech sleepers was tested, and simultaneously compared to standard PS-94 pre-stressed pretensioned concrete sleepers. The results exceeded all expectations, because both types can be considered comparable.” the CEO of Nasycalnia adds.

At static load, beech sleepers had flexural strength in the bottom of rail similar to the pre-stressed pretensioned concrete sleepers, and significantly exceeding the strength of the concrete sleepers in the middle section. Obviously, under dynamic load the strength was lower, but this results directly from the fact that wooden sleepers significantly suppress energy in comparison to the PS-94 sleepers.

Alongside the tests confirming the parameters and suitability of beechwood for the railway industry, Nasycalnia Podkładów in Czeremcha carried out the certification process for beech turnout sleepers. Today, as the only sleeper treatment plant in Poland, it also offers, besides beech sleepers, this infrastructural component which, it’s worth noting, is approved by the Railway Transport Office (UTK). In the view of the investment boom and serious lack of oak on the market, this is a good solution for contractors looking for surface solutions based on hardwood. It should also be remembered that the Czeremcha-based company, as the only domestic sleeper treatment plant, offers precise perforation of elements as well as a ready-to-assemble range of turnout sleepers manufactured according to the turnout coordinates of the mother company, KZN Bieżanów. This is a significant facilitation and acceleration of the construction process, especially in the face of short track closures.

During the work of the Railway Institute, issues arising directly from the PN-EN 13145 + A1: 2012 standard related to cracking of sleepers and turnout sleepers were also confirmed. “Many people in the industry have the misconception that surface cracks result from material defect. Meanwhile, it should be remembered that, unlike concrete, wood is not a homogeneous material but a natural composite. In the process of seasoning, there are natural processes that can cause such surface cracks, which are not defects. Moreover, many specialists claim that they demonstrate a good preparation of the feedstock before the treatment process.” says Ryszard Sokołowski.