Abstract: This disclosure describes formulations, systems and methods for coal topping, a term which refers to the application of liquid products to the top of coal loads, such as those in open topped coal hopper railcars as commonly used today to transport coal. Disclosed herein are controlled viscosity fluid formulations suitable for use as a coal topper. The fluids include water as a base solvent, polymer and, optionally, crosslinking agents and plasticizer. The polymer is a water-soluble polymer with reactive groups capable of producing viscosity in the solvent and reacting with crosslinking agents and the plasticizer. The polymer is one capable of manipulation to produce appropriate viscosity levels on a consistent basis. Crosslinking agents consist of chemicals capable of reacting with the reactive polymer to produce complexes that become essentially insoluble on drying. The plasticizer is an agent capable of providing for a dried matrix with flexibility without loss of strength.