; and (B) does not include any such effort required by the good faith belief of such employees that an abnormally dangerous condition exists at the place of employment of such employees. ; and (B) in section 8(b) ( 29 U.S.C. 158(b) )— (i) in paragraph (6), by striking and after the semicolon; (ii) in paragraph (7), by striking the period at the end of the matter following subparagraph (C) and inserting a semicolon; and (iii) by adding at the end the following: (8) in representing, or seeking to represent, employees engaged in maritime employment, to engage in a labor slowdown at any time, including when a collective-bargaining agreement is in effect; and . (3) Prohibiting labor organizations from blocking modernization at ports Section 8(b) of the National Labor Relations Act ( 29 U.S.C. 158(b) ), as amended by paragraph (2)(B), is further amended by adding at the end the following: (9) in representing, or seeking to represent, employees engaged in maritime employment, to— (A) impede or attempt to impede modernization efforts at a port, which thereby interferes with or otherwise impedes economic activity in relation to the national supply chain; or (B) interfere with or otherwise impede the servicing of any automated vessel operating without a crew. . (4) Preventing unfair labor practices Section 10(l) of the National Labor Relations Act ( 29 U.S.C. 160(l) ) is amended in the first sentence, by striking or section 8(b)(7) and inserting or paragraph (7), (8), or (9) of section 8(b) . (b) Amendments to the Labor Management Relations Act, 1947 Section 303 of the Labor Management Relations Act, 1947 ( 29 U.S.C. 187 ) is amended— (1) in subsection (a), by striking in section 8(b)(4) and inserting under paragraph (4), (8), or (9) of section 8(b)