USA Banner
  U.S. flag
              An official website of the United States government Here's how you knowOfficial US Government Icon
              **Official websites use .gov**A **.gov** website belongs to an official government organization in the United States.
            Secure Site Icon
              **Secure .gov websites use HTTPS**
                  A **lock** ( A locked padlock ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. 
 U.S. Department of Transportation Icon United States Department of Transportation
 Search DOT
            Search
                        About FRAAbout FRA
  

        
              Overview
                Organization
                Program Offices
                Resource Center
                Web Policies and Notices
                Contact Us
                Communications
                Governmental AffairsFeatured
  

        
              Bipartisan Infrastructure Law Information from FRA
                Careers
                Leadership Profiles
                Organizational Chart
                Newsroom
                Press Releases
                Speeches
                Fact Sheets
                TestimonyRailroad SafetyFeatured
  

        
              Train Horn Rule/Quiet Zones
                Public Blocked Crossings Incident Reporter
                Drug & Alcohol
                Safety Data
                C3RS
                High-Hazard Flammable Train Route AssessmentRailroad Safety
  

        
              Overview
                Railroad Crossing Safety & Trespass Prevention
                Accident Data & Reporting, Investigations
                Divisions
                Partnerships & ProgramsRail Network DevelopmentFeatured
  

        
              High-Speed Rail
                Amtrak
                Environmental Reviews
                GIS Maps
                RuralRail Network Development
  

        
              Overview
                Passenger Rail
                Freight Rail
                Environment
                Planning
                International
                Maps & Data
                Training & GuidanceResearch & DevelopmentFeatured
  

        
              R&D Current Projects
                Positive Train Control
                Hazardous Materials
                Highway-Rail Grade Crossing
                Close Call Reporting
                Broad Agency AnnouncementResearch & Development
  

        
              Overview
                Program Areas
                R&D ReportsLegislation & RegulationsFeatured
  

        
              FAST Act
                National Rail Plan
                Proposed State Rail Plan
                Civil PenaltiesLegislation & Regulations
  

        
              Overview
                Legislation
                Regulations & Rulemaking
                Buy AmericaGrants & LoansFeatured
  

        
              FRA Discretionary Grant Program Tool
                Discretionary Grant Calendar
                Railroad Capital Project Guidance
                FRA Webinars
                DOT GrantsGrants & Loans
  

        
              Overview
                Grant Programs
                Applying for Grants
                Resources for Grant Recipients
                Training & GuidanceFRA eLibraryeLibrary
  

        
              Accidents & Fatalities
                Compliance
                Conferences & Presentations
                Emergency & Safety
                Enforcement & Litigation
                Publications & Policy
                Reports
                OtherMenu Home


            
            Full Moving Block Concept and Requirements Specification for Railroad Operations
      

      
  Document Series
              Technical Reports


      
  Author
          Federal Railroad Administration


      
Report Number
              DOT/FRA/ORD-24/03

  Office
              RDI-23


      Subject
                    Communications,
                    Train Control


      
  Keywords
              Full Moving Block, FMB, Interoperable Train Control (ITC), Overlay Positive Train Control (O-PTC), Quasi-Moving Block (QMB), Alternative Broken Rail and Rollout Detection/Alternative Broken Rail Detection (ABRRD/ABRD)


      

      
      
              
                  
      
              
  Document
              FMB Concept and Specs.pdf (803.07 KB)

      
              
      
            
      
        		*DOT is committed to ensuring that information is available in appropriate alternative formats to meet the requirements of persons who have a disability. If you require an alternative version of files provided on this page, please contact
  					FRADevOps@dot.gov.*
  		
              Last updated: Tuesday, January 16, 2024 U.S. DEPARTMENT OF TRANSPORTATION

**Federal Railroad Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
                    About Us
  

        
              About FRA
                Careers
                Contact Us
                FRA Civil Rights
                Doing Business with FRA
                Grants and Financial Assistance
                Safety Management TeamsAreas of Interest
  

        
              Bipartisan Infrastructure Law
                Safety Data
                Buy America
                Operation Lifesaver
                Railroad Safety Advisory Committee
                FRA Secure Area
                Proactive DisclosureI Am A...
  

        
              Railroad Traveler
                Railroad Inspector
                Reporter
                Educator/StudentPolicies, Rights, Legal
  

        
              About DOT
                Budget and Performance
                Civil Rights
                FOIA
                Information Quality
                No FEAR Act
                Office of Inspector General
                Privacy Policy
                USA.gov
                Vulnerability Disclosure Policy
                Web Policies and Notices
                Web Standards