Inclusion Criteria:  Written Informed Consent consistent with International Conference on Harmonization Tripartite Guideline for Good Clinical Practice (ICH-GCP) and local laws signed prior to entry into the study (and prior to any study procedure including shipment of pre- existing High Resolution Computer Tomography (HRCT), spirometry or other medical records to reviewer). Male or female patients aged >= 18 years at Visit 1. Progressive Fibrosing Coal Mine Dust-Induced Interstitial Lung Disease (PF-CMD- ILD) based on a history of at least 5 years' work in surface or underground coal mining and presence of Progressive Massive Fibrosis (PMF) within 24 months of screening visit; or small opacity pneumoconiosis plus decline in percent predicted FVC of > 10% relative to high quality spirometry performed 12-24 months prior to screening visit, as assessed by the investigator. Pneumoconiotic changes documented on screening chest HRCT. Must include large opacities consistent with PMF or small opacities consistent with pneumoconiosis (as described previously). Carbon Monoxide Diffusion Capacity (DLCO) corrected for Hemoglobin (Hb) ≥ 30% and <80% predicted of normal at screening visit. FVC >= 45% predicted at screening visit.  Exclusion Criteria:  For those with PMF and past spirometry data, stable lung function based on a fall in percent predicted FVC of < 10% relative to most recent high quality spirometry obtained at least 12 months but no more than 5 years prior to screening Continued employment in a job such as active mining associated with ongoing coal mine dust or respirable crystalline silica dust exposure. Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT) > 1.5 x Upper Limit of Normal (ULN) at screening visit. Bilirubin > 1.5 x ULN at screening visit. Creatinine clearance <30 mL/min calculated by Cockcroft-Gault formula at screening visit.  Patients with underlying chronic liver disease (Child Pugh B or C hepatic impairment). Child Pugh A patients may be enrolled and started at a dose of 100mg BID  Previous treatment with nintedanib or pirfenidone. Other investigational therapy received within 1 month or 6 half-lives (whichever was greater) prior to screening visit. Use of any of the following medications for the treatment of Interstitial Lung Disease (ILD): azathioprine (AZA), cyclosporine, MMF, tacrolimus, oral corticosteroids (OCS) >20mg/day and the combination of OCS+AZA+NAC within 4 weeks of Visit 2, cyclophosphamide within 8 weeks of Visit 2, rituximab within 6 months of screening visit. The eligible patients with comorbid rheumatoid arthritis (RA) or other connective tissue diseases (CTD) is expected to be on disease- modifying anti-rheumatic drug (DMARD) e.g. methotrexate or TNF inhibitors. All approved RA/CTD medications are allowed at stable doses at baseline and during the study. Diagnosis of Idiopathic Pulmonary Fibrosis (IPF) based on American Thoracic Society (ATS)/ European Respiratory Society (ERS)/Japanese Respiratory Society (JRS)/Latin American Thoracic Association (ALAT) 2011 Guidelines.  Significant Pulmonary Arterial Hypertension (PAH) defined by any of the following  Previous clinical or echocardiographic evidence of significant right heart failure History of right heart catheterization showing a cardiac index <= 2 l/min/m² PAH requiring parenteral therapy with epoprostenol/treprostinil In the opinion of the Investigator, other clinically significant pulmonary abnormalities. Major extrapulmonary physiological restriction (e.g. chest wall abnormality, large pleural effusion)  Cardiovascular diseases, any of the following:  Severe hypertension, uncontrolled under treatment (≥160/100 mmHg), within 6 month of Visit 1 Myocardial infarction within 6 months of Visit 1 Unstable cardiac angina within 6 months of Visit 1  Bleeding risk, including any of the following:  Known genetic predisposition to bleeding.  Patients who require  Fibrinolysis, full-dose therapeutic anticoagulation (e.g. vitamin K antagonists, direct thrombin inhibitors, heparin, hirudin) High dose antiplatelet therapy. [Note: Prophylactic low dose heparin or heparin flush as needed for maintenance of an indwelling intravenous device (e.g. enoxaparin 4000 I.U. s.c. per day), as well as prophylactic use of antiplatelet therapy (e.g. acetyl salicylic acid up to 325 mg/day, or clopidogrel at 75 mg/day, or equivalent doses of other antiplatelet therapy) are not prohibited]. History of hemorrhagic central nervous system (CNS) event within 12 months of screening visit.  Any of the following within 3 months of screening visit:  Hemoptysis or hematuria Active gastro-intestinal (GI) bleeding or GI - ulcers Major injury or surgery (Investigators judgment). Coagulation parameters: International normalized ratio (INR) >2, prolongation of prothrombin time (PT) and activated partial thromboplastin time (aPTT) by >1.5 x ULN at Visit 1. History of thrombotic event (including stroke and transient ischemic attack) within 12 months of screening visit. Known hypersensitivity to the trial medication or its components (i.e. soya lecithin) Patients with peanut allergy. Other disease that may interfere with testing procedures or in the judgment of the Investigator may interfere with trial participation or may put the patient at risk when participating in this trial. Life expectancy for disease other than ILD < 2.5 years (Investigator assessment). Planned major surgical procedures. Women who are pregnant, nursing, or who plan to become pregnant while in the trial. Women of childbearing potential not willing or able to use highly effective methods of birth control per ICH M3 (R2) that result in a low failure rate of less than 1% per year when used consistently and correctly as well as one barrier method for 28 days prior to and 3 months after nintedanib administration. A list of contraception methods meeting these criteria is provided in the patient information. A woman is considered of childbearing potential, i.e. fertile, following menarche and until becoming post- menopausal unless permanently sterile. Permanent sterilization methods include hysterectomy, bilateral salpingectomy and bilateral oophorectomy In the opinion of the Investigator, active alcohol or drug abuse that will preclude the patient from adhering to the protocol. Patients not able to understand or follow trial procedures including completion of self- administered questionnaires without help. A study subject may not participate in another research study while participating in this research study.