Kirby Corporation Acquisition of Stewart & Stevenson  Conference Call Reference Materials  June 13, 2017 

 Forward-Looking Statements   Statements contained in this document with respect to the future are forward-looking statements. These statements reflect management’s reasonable judgment with respect to future events. Forward-looking statements involve risks and uncertainties. Actual results could differ materially from those anticipated as a result of various factors, including cyclical or other downturns in demand, significant pricing competition, unanticipated additions to industry capacity, changes in the Jones Act or in U.S. maritime policy and practice, fuel costs, interest rates, weather conditions and timing, magnitude and number of acquisitions made by Kirby. Forward-looking statements are based on currently available information and Kirby assumes no obligation to update any such statements. A list of additional risk factors can be found in Kirby’s annual report on Form 10-K for the year ended December 31, 2016 filed with the Securities and Exchange Commission.   2017 Acquisition of S&S  1 

 Acquisition Overview  2  2017 Acquisition of S&S 

 Acquisition Rationale  Expanded Geographic Presence: Distributor territories are a natural complement to the legacy distribution and services business, and will enhance our customer service and support capabilitiesStrategic Flexibility: Achieves significantly greater size, scale and scope for Kirby’s distribution and services segment which widens Kirby’s strategic opportunity setCustomer Profile: S&S customer base includes more industrial, non-oil & gas companies which should contribute more ratable, predictable revenues and earnings for Kirby’s distribution and services segment Revenue Mix: 75/25 distribution/manufacturing, compared to land-based distribution and services business of approximately 50/50, historically. Distribution revenues are less volatile than manufacturing Synergies and Efficiencies: Expected synergies of $25 million in the first two years. Operational efficiencies in leveraging best practices across S&S and legacy business. Additional upside from integration of S&S engineering and proprietary systems in current manufacturing processes and product offerings  2017 Acquisition of S&S  3 

     Stewart & Stevenson Company Overview  2017 Acquisition of S&S  4  Manufacturing TechnologiesBusiness Description:Four facilitiesDiverse and comprehensive product offeringFrac equipmentRigsSeismicSwitchgear and drive systemsRail King mobile railcar movers Complements with Kirby portfolio:Access to S&S designs and controlsAdditional product diversity in rigs, seismic, switchgears, and Rail King productsAdditional manufacturing capacity  DistributionBusiness Description:Allison, MTU, DTNA, EMD and Deutz distribution 42 branchesRental equipment business with 1,400 pieces of equipment including generators, load banks, fork lifts, pumps, compressors, and Rail King unitsComplements with Kirby portfolio:EMD business Contiguous territory across major shale basins (Eagle Ford, Permian, SCOOP) Opportunities in rental businessOpportunities to grow in other end markets 

                       Kirby and Stewart & Stevenson Locations  2017 Acquisition of S&S  5                                                                                                                                                                                                                                                                                Houston  Seattle    Chesapeake    Rocky Mount    Paducah    Tampa    Mobile            Shreveport  Baton Rouge  Lafayette / New Iberia  Belle Chase/Harvey    Houma    Little Rock  Oklahoma City              Tulsa  Austin  San Antonio  Laredo  Pharr    Thorofare    Cotulla    Corpus Christi    Odessa    Marlborough    Middletown    Albany  NYC      Piscataway                        Fort Myers  Miami  Fort Lauderdale  West Palm Beach  Fort Pierce  Orlando  Jacksonville  Ocala  Panama City        Stuttgart                  Waco  Dallas  Longview    Wichita Falls  Lubbock          Great Bend  Liberal  Denver            Casper  Farmington  Albuquerque  El Paso  Phoenix    Grand Junction      United Holdings  Kirby Engine Systems      Stewart & Stevenson  Locations / Branches  Allison / MTU / DTNA Territories  United Holdings  Stewart & Stevenson      EMD Territories  Kirby Engine Systems        Stewart & Stevenson