Timothy D. Stark
Timothy D. Stark
Advancement of Rail Ballast Testing Methodologies and …
— Two decades of advancement in process simulation testing of ballast strength, deformation, and degradation. Railroad Ballast Testing and Properties, ASTM STP1605: 1-28. Google Scholar. Kaewunruen, S. and Remennikov, A.M. (2009). Dynamic crack propagations in prestressed concrete sleepers in railway track systems subjected …
Flow cytometry, microscopy, and DNA analysis as …
— Ballast water, which is used for the stability of ships, is the main vector for the introduction of marine invasive species (Gollasch 2006; Molnar et al. 2008).Invasive species can pose a risk to marine ecosystem services (Levine 2008).They can negatively affect biodiversity (Molnar et al. 2008), increase the probability of disease transmission, …
The Ultimate Guide to Applicant Screening (+ Question …
Proper training for all team members involved in the screening process is key to a cohesive and effective recruitment strategy. This training should cover the operational use of recruitment technologies and the principles of fair and consistent candidate assessment. Training on evaluating candidates objectively, based on both job requirements ...
A Fuzzy Ballast Water Risk Assessment Model in Maritime …
— Recent years have witnessed a growing awareness of the critical role that maritime transport plays in global sustainability, given its significant environmental, economic, and social impacts. Central to this concern is the management of ballast water, which, if not properly treated, can lead to the introduction of invasive species, …
Large-scale triaxial and box testing on railroad ballast: a …
— The use of railway transportation systems has been increased throughout the years. The conventional ballasted tracks have been used widely in many countries around the world. Ballast material is the basic element of ballasted tracks. Ballast degrades and deforms after service. Therefore, periodical ballast maintenance is needed which is …
Principles of Degraded Ballast and Their Track Safety …
To help determine if and how a fouled ballast may pose a safety risk, the authors considered the soil mechanics principles that govern granular material response to …
An overview on the treatment of ballast water in ships
— Filtration is an effective screening process in the ballast water treatment. Mostly treatment systems use filters as physical separation treatment to remove larger organisms (i.e., size ≥50 μm). Filter mesh size of ≥50 μm are widely used (Sukizaki et al., 2013). Filtration steps are combined with gravity separation to remove large ...
CN2040114U
The railway ballast screening machine not only can improve workmen's labor intensities and working environments, but also can ensure the quality of ballast screening. Therefore, the qualities of the large and the medium maintenances are raised. ... Manufacturing process of wear-resistant raking tooth for railway sieve cleaner CN103703187A ...
Investment Process – Ballast Advisors
Our investment committee selects assets through a rigorous, unbiased evaluation and screening process. To maintain a broadly diverse portfolio, we select assets and products from across all asset classes, including global and domestic equities, taxable and non-taxable fixed income and a variety of alternative investments. ... Ballast Advisors ...
An overview on the treatment of ballast water in ships
— Filtration is an effective screening process in the ballast water treatment. Mostly treatment systems use filters as physical separation treatment to remove larger organisms (i.e., size ≥50 μm). Filter mesh size of ≥50 μm are widely used (Sukizaki et …
Further Development of Mechanised Ballast Cleaning
Further Development of Mechanised Ballast Cleaning the chain guides directly to the screening unit. This process already achieves a certain degree of separation of the spoil …
Ballast Cleaning Machine
— The machine has the following basic units:-- Excavating wheel and scarifier - Hopper assembly /bucket - Screen drive assembly - Broom assembly - Conveyor system Heavy-duty Scarifier breaks up the mud pockets underneath the sleeper ends to allow the track to drain.The ballast is transferred to the screening unit by the excavating wheel …
Railway ballast performance: Recent advances in the …
— Degradation and fouling: High contact forces and ballast layer vibration can increase the ballast wear rate, which results in an increased volume of fines within the ballast matrix. These result in more rapid ballast settlement rate particularly in wet conditions. For high-speed railways, ballast abrasion is a common degradation type, …
Railway & Rail Track Ballast Waste Recycling Solutions
Railway ballast that has lost its geotechnical properties and is no longer able to fully support the rail track or provide adequate drainage has to be renewed. However, rather than sending the old ballast to landfill, much of this spent material can be turned into valuable recycled products by an effective washing and screening process.
Ballast cleaning machines
The cleaned ballast coming from the screening unit can be transported via hydraulically adjustable baffles and slewing distributor conveyor belts or unloaded directly into the track. This technology of ballast placement allows the height of the track to be regulated exactly.
Railway ballast layer inspection with different GPR antennas …
— The full-scale ballasted track construction process is shown in Fig. 3. The ballast layer is constructed by placing the ballast and fouling with calculated mass in 2 layers. The ballast layer is constructed by placing the ballast and fouling of calculated mass in 2 layers. For each layer, ballast was firstly place and then is the fouling material.
Machines of choice
The ballast cleaner can be fitted with a wide cutterbar for screening switches and crossings or a narrow cutterbar for screening ballast in tunnels, bridges and other restricted areas. The RM74 machines have been working in South Africa since 1979 and are much respected in South Africa for their high quality of work and production achieved.
Geogrid reinforcement of ballasted railway superstructure for
— The reason for choosing this 700-m long section was that continuous intensive geometrical deterioration was observed in the 1999–2010 interval; because a ballast screening process was planned in 2010 with the elimination of the big water pockets shown in Fig. 6. Therefore, it was an opportunity in the Hungarian State Railways (MÁV) that …
Identification of Ballast Fouling Status and Mechanized …
— Systematic assessment of ballast fouling and mechanized cleaning efficiency through ground penetrating radar (GPR) is vital to ensure track stability and safe train transportation. Nevertheless, conventional methods of ballast fouling inspection and evaluation impede construction progress and escalate the cost of maintenance. This …
Quantification of the Mechanized Ballast Cleaning …
— To overcome ballast fouling, mechanized ballast cleaning process, which increases track occupancy time and cost, is usually used. Hence it is of crucial significance to identify at which stage of track …
Plasser & Theurer: Machine
The global standard in ballast cleaning – for use on plain-line tracks, can be expanded for turnouts as well; Also suitable for lines with low axle loads (C2) Excavates material efficiently using a powerful excavating chain guided through the cutter bar; Exceptional cleaning quality thanks to triple-deck ballast screening
Railway ballast characteristics, selection criteria …
— ABSTRACT This work is a comprehensive investigation to find to what extent simple laboratory tests e.g. Los Angeles abrasion and micro-Deval might be suitable for predicting real railway ballast ...
Ballast – Functions and Types – theconstructor
Ballast is a granular material which is placed and packed below and around the railway sleepers. Different types of ballast materials used are broken stone, sand, gravel, moorum, brickbats etc. The main purpose of ballast is to transmit ...
Review of ballast track tamping: Mechanism, challenges and …
— The process of ballast tamping and compaction is considered in many studies. ... the LSF series automatic filter is the first step of a system specially designed for the screening of ballast water ...
(PDF) Developing Track Ballast Characteristic Guideline In …
— This study aims to quantify the degree of degradation of ballast and aid in the decision process to replace the ballast bed, based on a detailed 3D scan of the ballast samples. Thirty ballast ...
Shoulder Ballast Cleaning
Shoulder ballast cleaning consists of removing ballast at the end of the ties, screening the ballast and discarding fines and fouling material and restoring the good ballast to the shoulder. Integrated scarifiers break open end of tie mud pockets, removes fines, and restores ballast voids in the shoulders and under the tie ends and release ...
Investigation and evaluation of railway ballast properties …
— The usual process for track or ballast renewal is based on some investigations about the track geometry and substructure and the efficiency of maintenance operations [16]. The bearing capacity depends on the qualities and thicknesses of soils that compose the subgrade, from the formation layer to the lower layers. ... full screening on …
CHAPTER 3 BALLAST CLEANING AND HANDLING …
The function of the Ballast Cleaning Machine is to carry out screening of full cross section of track ballast by excavating existing fouled ballast and then putting back clean ballast …
Research on Railroad Ballast Specification and …
Research on Railroad Ballast Specification and Evaluation GERALD P. RAYMOND ABSTRACT Research leading to recommended procedures for ballast selection and grading are presented. The ballast selection procedure is also presented and offers a sequential screening process to eliminate undesirable materials. The procedure