Longwall unit shift productivity for American coal operators in 1987 jumped an astonishing 30% over a strong 1986 performance. A survey of 48 of the 96 operating faces for 1987 indicates unit shift productivity rose from 1,234 clean tons of coal in 1986 to 1,609 tons in 1987. This continues the strong upward trend of the past two years that has seen average unit shift productivity rising 47%, from 1,092 clean tons to 1,609 tons. The accompanying table shows the detailed results from the 1987 Longwall Productivity Survey. The survey results from 48 faces are separated into three cutting ranges: high (80 to 120 in.; medium (53 to 80 in.); and low (below 53 in.). Average, maximum and minimum values are shown for each range. The high cutting range (80 to 120 in.) showed the best productivity increase (39%), rising from 1,603 tons per unit shift to 2,223 tons in the span of a year. Frequency and difficulty of equipment moves, however, prevented this increase from fully benefiting the total face tons per man-day, which rose only 20% to 156 tons.

Longwall productivity continues upward trend, jumps 30% in year's time

This investigation was primarily aimed to examine the probable causes of sudden failure of one of the rear shield chock for longwall face in a colliery. The rear shield was made of micro alloyed steel and a through thickness fracture was observed in the 63 mm rear shield plate. Preliminary visual examination, nondestructive evaluation including dye-penetrant and magnetic particle testing, evaluation of mechanical properties, detailed optical and scanning electron microscopic analysis were the necessary supplements to this investigation. Finally, a study on residual stress measurement and effect of pulsating load on structural integrity was carried out. The outcome of the investigation infers that improper welding caused adverse metallurgical and stress conditions leading to sudden failure of the rear shield plate.

Failure Analysis of a Rear Wall Chock Shield for Longwall Face in Coal Mines

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

B.N. Das

Author Tools

Chat about Author

Papers

Failure Analysis of a Rear Wall Chock Shield for Longwall Face in Coal Mines