JP4477255B2

JP4477255B2 - Submarine laid long body laid ship

Info

Publication number: JP4477255B2
Application number: JP2001083068A
Authority: JP
Inventors: 健一石井
Original assignee: Furukawa Electric Co Ltd
Current assignee: Furukawa Electric Co Ltd
Priority date: 2001-03-22
Filing date: 2001-03-22
Publication date: 2010-06-09
Anticipated expiration: 2021-03-22
Also published as: JP2002281626A

Description

【０００１】
【発明の属する技術分野】
本発明は、海底送水管、海底送油管、海水取水用管等の流体輸送管、電力、通信（光通信を含む）用の海底ケーブル等の海底布設長尺体を海底に布設（埋設を含む）するための海底布設長尺体布設船に関するものである。
【０００２】
【従来の技術】
従来の海底布設長尺体布設船は、海底布設長尺体を収納する長尺体収納部と、海底布設長尺体を海中に落とし込む速度を制御するブレーキ装置と、海底布設長尺体を海中に落とし込むシュータとを備えている。そして、この布設船を用いて、海底布設長尺体を海底に布設する場合には、予め長尺体収納部に海底布設長尺体を収納した布設船を海上で所定の布設ルートに沿って曳船により曳航する。これと同時に、長尺体収納部から海底布設長尺体を引き出し、ブレーキ装置で所定の落とし込み速度に制御しながら、シュータにより布設船の船尾又は船首から海中に落とし込み、海底に布設することにより行う。なお、海底に布設した海底布設長尺体は必要に応じて海底に埋設する。
【０００３】
ところで、海底布設長尺体を布設船から海中に落とし込むために用いるシュータは、海底布設長尺体を海中に落とし込む際、海底布設長尺体を許容曲率半径以上に維持すると共に、海底布設長尺体に加わる側圧を許容側圧以下に抑制するために不可欠な装置である。そして、その海底布設長尺体と接触する滑走面の摩擦係数を小さくし、海底布設長尺体との摩擦抵抗を軽減して、シュータを通過して海中に落ちる海底布設長尺体に大きなブレーキ力が作用しないようにし、海底布設長尺体を海中に落とし込むようになっている。
【０００４】
また、海底布設長尺体を海中に落とし込む速度を制御するブレーキ装置に必要とされる制御力、即ち、ブレーキ力Ｆは、海底に布設される海底布設長尺体の布設水深ｈと海底布設長尺体の単位長さ当りの水中重量Ｗに大きく依存し、海底布設長尺体がシュータを通過する際にシュータから受ける摩擦抵抗を前記により無視すると、下記（１）式に示すような関係になる。
【０００５】
【数１】
Ｆ＝Ｗｈ・・・・・（１）
【０００６】
従って、海底布設長尺体の布設水深ｈが深くなるに伴い、ブレーキ装置に必要とされるブレーキ力Ｆが大きくなる。
【０００７】
【発明が解決しようとする課題】
最近、各地で比較的水質が良好で栄養分を多く含み、且つ、低温度の海洋深層水の開発利用が進み、この深層水を海上又は陸上にくみ上げ輸送するために用いる取水用管の海底への布設水深が急激に深くなる傾向にある。このような水深の深い海域の海底に取水用管を布設する場合には、その布設時に前記布設船の船尾又は船首で支持すべき取水用管水中重量が増大化してくるので、この水中重量の大部分をブレーキ装置で支える必要があり、そのブレーキ装置において、取水用管を布設船から海中に落とし込む速度を制御するために必要となるブレーキ力が非常に大きくなってくる。そうすると、そのブレーキ装置を駆動する動力及び各部機構の機械的強度を大きくする必要があり、ブレーキ装置が大型、大重量化し、大幅なコストアップを引き起こす問題があった。
【０００８】
また、ブレーキ装置で取水用管を把持する把持力も必然的に増加して中空の取水用管に許容される側圧を越える大きな側圧が加わり、中空の取水用管が圧縮されて座屈破壊を引き起こす恐れもあった。
【０００９】
このような問題は、前記取水用管以外の海底布設長尺体である海底送水、送油管等の流体輸送管を水深の深い海域の海底に布設する場合にも生じていた。
更に、前記流体輸送管以外の海底布設長尺体である、例えば、海底ケーブルを海底布設する場合には、前記取水用管の場合ほど、水深の深い海域の海底に布設するケースが少ないけれども、前記取水用管よりも単位長さ当りの水中重量が一般に大きいので、布設水深が少し深くなってくると、同様にブレーキ装置の駆動制御に必要となるブレーキ力が大きくなり、ブレーキ装置が大型、大重量化してコストアップを引き起こすほか、海底ケーブルに許容側圧を越える過大な側圧が加わり、海底ケーブルが変形や損傷して電気的特性や信号伝送特性を低下させる恐れがあった。
【００１０】
本発明は上記の課題を解決するためになされたもので、海底布設長尺体を海中に落とし込む速度を制御するブレーキ装置の大型、大重量化を防ぎ、且つ、ブレーキ装置に加わる側圧が過大にならないようにした海底布設長尺体布設船を提供することを目的とする。
【００１１】
【課題を解決するための手段】
上記の目的を達成するために、本発明は、海底布設長尺体を収納する長尺体収納部と、海底布設長尺体を海中に落とし込む速度を制御するブレーキ装置と、海底布設長尺体を海中に落とし込むシュータとを備えた海底布設長尺体布設船において、前記シュータの海底布設長尺体と接触する滑走面に、海底布設長尺体との摩擦抵抗を増大させるための高摩擦抵抗層を設けてなるもので、前記高摩擦抵抗層は、海底に布設された海底布設長尺体を前記布設船に引き揚げる方向の摩擦抵抗が海底布設長尺体を布設船から海中に落とし込む方向の摩擦抵抗よりも小さくなるように、摩擦係数に方向性を持たせてなることを特徴とするものである。
【００１２】
上記構成によると、布設船からブレーキ装置を経由してシュータの滑走面を滑りながら海中に落とし込まれる海底布設長尺体は、シュータの滑走面に設けた高摩擦抵抗層による摩擦抵抗の作用で、海底布設長尺体を海中に落とし込む方向とは逆方向へ引き揚げようとするブレーキ力が大きく働く。そうすると、海底布設長尺体の布設水深が深くなり、その布設時に海底布設長尺体の水中重量が増大化しても、その水中重量をブレーキ装置だけでなく、シュータの方でも支えることになり、ブレーキ装置で海底布設長尺体を海中に落とし込む速度を制御するために必要となるブレーキ力が減少する。従って、ブレーキ装置を駆動制御する動力及び各部機構の機械的強度を小さくすることが可能になり、ブレーキ装置の小型、軽量化及びコストダウンを図ることができる。
【００１３】
また、ブレーキ装置で必要となるブレーキ力が減少すると、海底布設長尺体の把持力も必然的に小さくなり、海底布設長尺体に許容側圧を越える過大な側圧が作用しなくなるので、海底布設長尺体の布設時に、海底布設長尺体が座屈破壊、変形又は損傷等を起こさなくなり、海底布設長尺体を水深の深い海域の海底に安全に布設することができる。
【００１５】
このように、前記高摩擦抵抗層の摩擦係数に方向性を持たせると、海底に布設された海底布設長尺体が投錨等により損傷し、布設船上に引き揚げて修理するような場合に、その海底布設長尺体を引き揚げる方向のシュータの摩擦抵抗が小さくなるので、海底布設長尺体を引き揚げるために要する引取り力を低減させることができる。従って、布設船上に設けた海底布設長尺体の巻取り回収設備を小型化することが可能になり、回収設備費用を低く抑えることができるほか、シュータの摩擦抵抗が加わることにより海底布設長尺体の引取り力が増大して、海底布設長尺体が回収途中で損傷を受ける恐れもなくなるので好ましい。
【００１６】
更に、本発明においては、前記高摩擦抵抗層の摩擦係数に方向性を持たせるために、該抵抗層の海底布設長尺体との接触面に、海底布設長尺体の落とし込み又は引き揚げ方向に沿って複数の断面不等辺三角形状の突起体を設け、該突起体のシュータ上方に位置する傾斜辺の長さをシュータ下方に位置する傾斜辺の長さよりも短く形成するようにしてもよい。
【００１７】
【発明の実施の形態】
以下、本発明の一実施形態を図面により詳細に説明する。図１は本発明の海底布設長尺体布設船１０を用いて海底布設長尺体である、例えば、海洋深層水の取水用管１２を海底１４に布設している状態を示す概要図である。本図に示す海底布設長尺体布設船１０は、取水用管１２を布設船上又は船内にじかに、又は布設船上又は船内に設置したターンテーブルやドラムにコイル状に巻回して収納する長尺体収納部１６と、取水用管１２を海中に落とし込む速度を制御するキャタピラ等のブレーキ装置１８と、取水用管１２を海中に落とし込むガイドとなるシュータ２０とを備えている。
【００１８】
シュータ２０は、図２（イ）（ロ）に示すように、開口を上部に向けた断面コ字状で、且つ、長さ方向に１／４円形状の樋型（ベンド型）をしており、本体は軟鋼、ステンレス鋼材等の金属材料で出来ている。そして、図１に示すように、前記布設船１０の船尾に、又は船首（図示せず）に設置される。このシュータ２０の内側底面は、取水用管１２と滑り接触しながら案内して海中に落とし込むための滑走面２０ａになっており、取水用管１２に無理な曲げが加わらないように、許容曲率半径以上を維持し、且つ、一定曲率半径で外側に凸状に湾曲して形成されている。
【００１９】
本発明の海底布設長尺体布設船１０は、前記シュータ２０の滑走面２０ａに、取水用管１２との摩擦抵抗を増大させるための高摩擦抵抗層２２を設けたことを特徴としている。この高摩擦抵抗層２２は、例えば、図２（ハ）に示すように、前記滑走面２０ａの形状に合致するように、弧状にわん曲した断面矩形状のゴム板状体（ゴムシート）２４からなり、底面を接着材等で滑走面２０ａ上に貼り付けることにより設ける。ゴム板状体２４は、ＥＰラバー、ウレタンゴム、ポリブタジエンゴム等の耐磨耗性、耐久性の優れたゴム材で出来ている。ゴム材を使用することにより、取水用管１２との接触面の摩擦係数が大きくなり、取水用管１２との摩擦抵抗を増大させることができる。
【００２０】
なお、ゴム板状体２４の取水用管１２との接触面に、図３に示すような多数の微小凹凸部２４ａを設けて接触面に粗面化処理を施すと、更に該接触面の摩擦係数が大きくなり、摩擦抵抗をより増大させることができる。前記摩擦係数は高摩擦抵抗層２２の材質やゴム板状体２４の接触面の凹凸状態（粗面状態）等を変更することに調節することができ、１．０程度の係数値のものまで容易に得ることもできる。
【００２１】
このように、シュータ２０の滑走面２０ａに高摩擦抵抗層２２を設けることにより、取水用管１２が前記滑走面２０ａを滑りながら海中に落ちるときの摩擦抵抗が増大し、シュータ２０のところで取水用管１２の落とし込みに対抗するブレーキ力が作用するため、ブレーキ装置１８で必要とされるブレーキ力、即ち、該装置１８で取水用管１２に働かせなければならないブレーキ力を軽減緩和することが出来る。そこで、シュータ２０の滑走面２０ａに設けた高摩擦抵抗層２２の表面（取水用管１２との接触面）における摩擦係数と前記ブレーキ装置１８で必要とされるブレーキ力との関係は下記（２）式のように求めることができる。
【００２２】
【数２】
Ｔ＝Ｗｈ／ｅ^μθ ・・・・・（２）
【００２３】
上記（２）式において、
Ｔ：シュータ２０の取水用管１２を導入させる入口側の後方張力（＝ブレーキ装置１８で必要とされるブレーキ力）
Ｗ：取水用管１２の単位長さ当りの水中重量
ｈ：布設水深
μ：高摩擦抵抗層２２の摩擦係数（取水用管１２を海中に落とし込むとき）
θ：高摩擦抵抗層２２の曲率（図２に示すものではπ／２）
【００２４】
水中重量が５０ｋｇ／ｍ級の可撓性を有する取水用管１２を水深１００ｍの海域の海底１４に布設する場合、前記高摩擦抵抗層２２の前記摩擦係数μをパラメータにしてブレーキ装置１８で必要とされるブレーキ力を試算してみると、下記表１のようになる。
【００２５】
【表１】

【００２６】
上記表１から明らかなように、海中に落とし込まれて海底１４に着底するまでの取水用管１２の水中重量は、ブレーキ装置１８ばかりでなく、シュータ２０でも支えることになるので、その水中重量を支える力が分散され、ブレーキ装置１８で必要とされるブレーキ力を減少させることが可能になる。また、高摩擦抵抗層２２の摩擦係数の増加によって、そのブレーキ力を指数関数的に低減させることができる。例えば、摩擦抵抗が殆どない場合に比較し、高摩擦抵抗層２２の摩擦係数が０．５の場合には、ブレーキ装置１８で受け持つブレーキ力を約１／２に、また、摩擦係数が１．０の場合には、そのブレーキ力を約１／５にまで低減させることができる。その結果、取水用管１２の布設水深が深くなり、その水中重量が増大しても、ブレーキ装置で負担するブレーキ力を軽減することができるので、ブレーキ装置を駆動制御する動力及び各部機構の機械的強度を小さくすることが可能になり、ブレーキ装置の小型、軽量化及びコストダウンを図ることができ、布設工事費用を削減することができる。
【００２７】
図４に示すものは、高摩擦抵抗層２２の取水用管１２との接触面、即ち、高摩擦抵抗層２２を構成するゴム板状体２４の取水用管１２との接触面に、取水用管１２の落とし込み方向又は引き揚げ方向（図２（イ）参照）に沿って連続的に複数の断面不等辺三角形状の突起体２６を設け、該突起体のシュータ上方に位置する傾斜辺２６ａの長さがシュータ下方に位置する傾斜辺２６ｂの長さよりも短くなるように粗面化処理を施し、取水用管１２の落とし込み方向には逆目、引き揚げ方向には順目となるようにしたものである。即ち、このような突起体２６を設けて前記接触面を粗面化処理することにより、海底１４に布設された取水用管１２を修理等のために前記布設船１０に引き揚げる方向の摩擦抵抗が、取水用管１２を布設のために前記布設船１０から海中に落とし込む方向の摩擦抵抗よりも小さくなるように、高摩擦抵抗層２２の前記接触面の摩擦係数に方向性を持たせたものである。
【００２８】
このように、前記高摩擦抵抗層２２の摩擦係数に方向性を持たせると、海底１４に布設された取水用管１２が投錨等により損傷し、布設船１０上に引き揚げて修理するような場合には、その取水用管１２を引き揚げる方向のシュータ２０の摩擦抵抗が、取水用管１２を落とし込む方向の摩擦抵抗よりも小さくなるので、取水用管１２を引き揚げるために要する引取り力を低減させることができる。従って、布設船１０上に設けた取水用管１２の巻取り回収設備（図示せず）、前記長尺体収納部１６がその回収設備を兼ねる場合には、その収納部１６を軽量小型化することが可能になり、回収設備費用を低く抑えることができるほか、取水用管１２の引き揚げに要する引取り力が減少するので、取水用管１２がその回収途中で過度に伸張又は側圧を受けて損傷する恐れもなくなり実用的である。
【００２９】
本発明の海底布設長尺体布設船１０を用いて取水用管１２を海底１４に布設する場合には、図１に示すように、予め長尺体収納部１６に取水用管１２を収納した布設船１０を海上で所定の布設ルートに沿って曳船１１により曳航する。これと同時に、長尺体収納部１６から取水用管１２を引き出し、ブレーキ装置１８で所定のブレーキ力を付加して落とし込み速度に制御しながら、また、シュータ２０により引き揚げ方向への摩擦抵抗を付与しながら、布設船１０の船尾又は船首から海中に落とし込み、海底１４に布設することにより行う。なお、海底１４に布設した取水用管１２は、必要に応じて、布設と同時又は布設後に、海底下に埋設する。なお、本発明の布設船１０で海底１４に布設する海底布設長尺体は、前記取水用管１２だけに限定されるものではなく、その他の流体輸送管や海底ケーブル等にも当然適用できるものである。
【００３０】
図５（イ）（ロ）に示すものは、図２に示すシュータ２０とは異なる構造のシュータ２８を示すものである。このシュータ２８は、２個の鉄製の半円管状体３０、３０を分割自在に組み合わせた二つ割り構造のベンド管で構成される。半円管状体３０、３０は、両側縁に取付け鍔３０ａ、３０ａを有し、長さ方向に１／４円形状となるように、且つ、許容曲率半径以上の一定曲率半径を維持するように外側に凸状にわん曲させた断面略半円形状に形成される。そして、これら半円管状体３０、３０を、半円形状凹部が対向するように重ね合わせ、両取付け鍔３０ａ、３０ａをボルト締めして締結することにより組み合わされ、中心部に取水用管１２等の海底布設長尺体を通す貫通穴３２が設けられる。この貫通穴３２は、海底布設長尺体の外径よりも１０〜２０％程度大きい内径を有し、内周面、即ち、滑走面には前記高摩擦抵抗層２２を構成するゴム板状体（ゴムシート）２４が内張りされる。ゴム板状体２４の内周面、即ち、海底布設長尺体との接触面には、必要に応じて、海底布設長尺体との摩擦抵抗を増大させるための前記粗面化処理を施してもよい。
【００３１】
このようなシュータ２８を用いると、海底布設長尺体のほぼ全周面をシュータ２８の高摩擦抵抗層２２に接触させて海中に落とし込むことが可能になる。従って、海底布設長尺体を落とし込むときの摩擦抵抗をより増大させ、ブレーキ装置１８で必要とされるブレーキ力を低減させ、その負担をより軽減することができるので好ましい。
【００３２】
なお、前記高摩擦抵抗層２２は、いずれもシュータ２０、２８の取水用管１２等の海底布設長尺体と接触する滑走面に、ゴム板状体２４を設けて構成される。そのほかに、前記滑走面自体に直に、例えば、前記したような、微小凹凸部２４ａや断面不等辺三角形状の突起体２６を設ける等の粗面化処理を施して高摩擦抵抗層（図示せず）を設けるようにしてもよい。
【００３３】
【発明の効果】
以上説明したように、本発明の海底布設長尺体布設船によれば、海底布設長尺体を海中に落とし込むシュータの海底布設長尺体と接触する滑走面に、海底布設長尺体との摩擦抵抗を増大させるための高摩擦抵抗層を設けたので、海底布設長尺体の布設水深が深くなり、その布設時に海底布設長尺体の水中重量が増大化しても、その水中重量をシュータの方でも支えることが可能になり、ブレーキ装置で必要とされるブレーキ力を減少させることができる。従って、ブレーキ装置を駆動制御する動力及び各部機構の機械的強度を小さくすることが可能になり、ブレーキ装置の小型、軽量化及びコストダウンを図ることができる。
【００３４】
また、海底布設長尺体の把持力も小さくなり、海底布設長尺体に許容側圧を越える過大な側圧が作用しなくなるので、海底布設長尺体の布設時に、海底布設長尺体が座屈破壊、変形又は損傷等を起こさなくなり、海底布設長尺体を水深の深い海域の海底に安全に布設することができる。
【００３５】
また、本発明の海底布設長尺体布設船において、前記シュータの海底布設長尺体と接触する滑走面に設けた高摩擦抵抗層として、海底に布設された海底布設長尺体を前記布設船に引き揚げる方向の摩擦抵抗が海底布設長尺体を布設船から海中に落とし込む方向の摩擦抵抗よりも小さくなるように、摩擦係数に方向性を持たせるようにしてもよい。このようにすると、海底に布設された海底布設長尺体を修理等のために布設船上に引き揚げるような場合に、その海底布設長尺体を引き揚げる方向のシュータの摩擦抵抗が小さくなるので、海底布設長尺体を引き揚げるために要する引取り力を低減させることができる。従って、布設船上に設けた海底布設長尺体の巻取り回収設備を小型化することが可能になり、回収設備費用を低く抑えることができるほか、海底布設長尺体の引き揚げに要する引取り力が減少するので、海底布設長尺体がその回収途中で過度に伸張又は側圧を受けて損傷する恐れもなくなる。
【図面の簡単な説明】
【図１】本発明の海底布設長尺体布設船の使用状態を示す概要図である。
【図２】本発明の海底布設長尺体布設船で使用するシュータの概要を示すもので、（イ）は正面図、（ロ）は右端面図、（ハ）は高摩擦抵抗層の一部を拡大した正面図である。
【図３】図２（ハ）の高摩擦抵抗層の変形例の一部を拡大した正面図である。
【図４】図２（ハ）の高摩擦抵抗層の更なる変形例の一部を拡大した正面図である。
【図５】本発明の海底布設長尺体布設船で使用するシュータの変形例の概要を示すもので、（イ）は正面図、（ロ）は右端面図である。
【符号の説明】
１０海底布設長尺体布設船
１１曳船
１２取水用管
１４海底
１６長尺体収納部
１８ブレーキ装置
２０シュータ
２０ａ滑走面
２２高摩擦抵抗層
２４ゴム板状体
２４ａ微小凹凸部
２６断面不等辺三角形状の突起体
２６ａ傾斜辺
２６ｂ傾斜辺
２８シュータ
３０半円管状体
３０ａ取付け鍔
３２貫通穴[0001]
BACKGROUND OF THE INVENTION
The present invention lays a submarine laying long body such as a submarine water pipe, a submarine oil pipe, a fluid transport pipe such as a seawater intake pipe, a submarine cable for power and communication (including optical communication) on the seabed (including embedment). This is related to a long-body submarine laying ship.
[0002]
[Prior art]
The conventional submarine laying long body laying ship has a long body storage part for storing a submarine laying long body, a brake device for controlling the speed of dropping the submarine laying long body into the sea, and a submarine laying long body underwater. And a shooter to drop into. And when laying a submarine laying long body on the sea floor using this laying ship, a laying ship in which the long seabed laying long body is stored in advance in the long body storage section along the predetermined laying route at sea. Towed by dredger. At the same time, the seabed laying long body is pulled out from the long body storage section, and controlled by the brake device to a predetermined drop speed, dropped into the sea from the stern or bow of the laying ship by the shooter, and laid on the seabed. . In addition, the seabed laying long body laid on the seabed is buried on the seabed as needed.
[0003]
By the way, the shooter used to drop the submarine laid long body from the laying ship into the sea keeps the submarine laid long body above the allowable curvature radius when dropping the seabed laid long body into the sea. It is an indispensable device for suppressing the lateral pressure applied to the body below the allowable lateral pressure. And the friction coefficient of the sliding surface that comes into contact with the submarine installation long body is reduced, the friction resistance with the submarine installation long body is reduced, and a large brake is applied to the submarine installation long body that passes through the shooter and falls into the sea. It is designed to prevent the force from acting and drop the long seabed laying body into the sea.
[0004]
Further, the control force required for the brake device for controlling the speed at which the long seabed laying body is dropped into the sea, that is, the braking force F, is determined by the laying depth h of the seabed laying long body laid on the seabed and the seabed laying length. It greatly depends on the underwater weight W per unit length of the scale, and if the frictional resistance received from the shooter when the seabed laid long body passes through the shooter is ignored, the relationship as shown in the following equation (1) is obtained. Become.
[0005]
[Expression 1]
F = Wh (1)
[0006]
Therefore, as the laying water depth h of the seabed laying long body becomes deeper, the braking force F required for the brake device increases.
[0007]
[Problems to be solved by the invention]
Recently, the development and utilization of deep seawater with relatively good water quality, high nutrient content, and low temperature has progressed in various places, and intake pipes used to pump up deep seawater to the sea or land are transported to the seabed. The laying water depth tends to increase rapidly. When laying intake pipes on the seabed in such deep sea areas, the weight of the intake pipes to be supported by the stern or bow of the laying ship at the time of laying increases. Most of them need to be supported by a brake device, and in that brake device, the braking force required to control the speed at which the intake pipe is dropped from the laying ship into the sea becomes very large. In this case, it is necessary to increase the power for driving the brake device and the mechanical strength of each mechanism, and there is a problem that the brake device becomes large and heavy, resulting in a significant increase in cost.
[0008]
In addition, the gripping force for gripping the water intake pipe with the brake device inevitably increases, and a large side pressure exceeding the allowable side pressure is applied to the hollow water intake pipe, and the hollow water intake pipe is compressed to cause buckling failure. There was also fear.
[0009]
Such a problem also occurs when a fluid transport pipe such as a seabed water supply or oil supply pipe, which is a long seabed laying body other than the intake pipe, is laid on the seabed in a deep sea area.
Furthermore, it is a submarine laying long body other than the fluid transport pipe, for example, when laying a submarine cable on the seabed, the case of laying on the seabed in a deep sea area is less as in the case of the intake pipe, Since the underwater weight per unit length is generally larger than that of the water intake pipe, when the laying water depth becomes a little deeper, the brake force necessary for the drive control of the brake device also increases, and the brake device is large. In addition to increasing the weight and increasing the cost, the submarine cable may be subjected to excessive side pressure exceeding the allowable side pressure, and the submarine cable may be deformed or damaged to deteriorate electrical characteristics and signal transmission characteristics.
[0010]
The present invention has been made in order to solve the above-described problems, and prevents the brake device that controls the speed at which the submarine laying long body is dropped into the sea from being large and heavy, and the side pressure applied to the brake device is excessive. An object is to provide a submarine-installed long-body-installed ship that is not required to be installed.
[0011]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a long-body storage unit that stores a long submarine laying body, a brake device that controls the speed of dropping the long submarine installation into the sea, and a long submarine installation. In a submarine installation long body laying ship equipped with a shooter that drops water into the sea, a high friction resistance for increasing the friction resistance with the submarine installation long body on the sliding surface of the shooter that contacts the submarine installation long body The high frictional resistance layer is formed in a direction in which the frictional resistance in the direction of pulling the seabed laying long body laid on the seabed onto the laying ship drops the seabed laying long body from the laying ship into the sea. The friction coefficient is given directionality so as to be smaller than the frictional resistance .
[0012]
According to the above configuration, the long submarine laying body that is dropped into the sea while sliding the sliding surface of the shooter from the laying ship via the brake device is caused by the frictional resistance of the high frictional resistance layer provided on the sliding surface of the shooter. The brake force that tries to lift the long undersea laying body in the direction opposite to the direction of dropping into the sea works greatly. Then, the laying water depth of the submarine laying long body becomes deep, and even if the underwater weight of the seabed laying long body increases during the laying, the underwater weight will be supported not only by the brake device but also by the shooter, The braking force required to control the speed at which the submarine laying long body is dropped into the sea by the brake device is reduced. Therefore, it is possible to reduce the power for driving and controlling the brake device and the mechanical strength of each mechanism, and the brake device can be reduced in size, weight, and cost.
[0013]
In addition, if the braking force required for the brake device is reduced, the gripping force of the long submarine laying body will inevitably decrease, and an excessive lateral pressure exceeding the allowable lateral pressure will not act on the long submarine laying long body. When the scale body is laid, the submarine laying long body does not cause buckling failure, deformation or damage, and the seabed laying long body can be safely laid on the seabed in a deep sea area.
[0015]
In this way, when the direction of the coefficient of friction of the high frictional resistance layer is given directionality, when the seabed laying long body laid on the seabed is damaged by dredging or the like and is lifted onto the laying ship for repair, Since the frictional resistance of the shooter in the direction of lifting the submarine laid long body is reduced, the take-up force required to lift the submarine laid long body can be reduced. Therefore, it is possible to reduce the size of the seabed laying and long recovery equipment installed on the laying ship, reducing the cost of the recovery equipment, and adding the frictional resistance of the shooter to the seabed laying and long equipment. This is preferable because the body take-up force is increased, and there is no possibility that the long seabed laying body is damaged during the recovery.
[0016]
Furthermore, in the present invention, in order to give directionality to the friction coefficient of the high friction resistance layer, the contact surface of the resistance layer with the seabed laying long body is placed in the dropping or lifting direction of the seabed laying long body. A plurality of protrusions having an unequal cross-sectional triangle shape along the shooter may be provided, and the length of the inclined side located above the shooter may be shorter than the length of the inclined side located below the shooter.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a state where a seabed laying long body, for example, a deep seawater intake pipe 12 is laid on a seabed 14 using a seabed laying long body laying ship 10 of the present invention. . The submarine laying long body laying ship 10 shown in this figure is a long body that accommodates a water intake pipe 12 directly on the laying ship or in the ship, or wound in a coil on a turntable or drum installed on the laying ship or in the ship. A storage unit 16, a brake device 18 such as a caterpillar for controlling the speed of dropping the water intake pipe 12 into the sea, and a shooter 20 serving as a guide for dropping the water intake pipe 12 into the sea are provided.
[0018]
As shown in FIGS. 2 (a) and 2 (b), the shooter 20 has a bowl shape (bend shape) having a U-shaped cross section with the opening facing upward and a ¼ circle shape in the length direction. The body is made of a metallic material such as mild steel or stainless steel. And as shown in FIG. 1, it installs in the stern of the said laying ship 10, or a bow (not shown). The inner bottom surface of the shooter 20 is a sliding surface 20a that is guided in sliding contact with the water intake pipe 12 and dropped into the sea, and an allowable radius of curvature is provided so that excessive bending is not applied to the water intake pipe 12. The above is maintained, and it is formed to be curved outwardly with a constant radius of curvature.
[0019]
The submarine laying long body laying ship 10 of the present invention is characterized in that a high frictional resistance layer 22 for increasing the frictional resistance with the water intake pipe 12 is provided on the sliding surface 20 a of the shooter 20. For example, as shown in FIG. 2C, the high friction resistance layer 22 is a rubber plate body (rubber sheet) 24 having a rectangular cross section bent in an arc shape so as to match the shape of the sliding surface 20a. It is provided by sticking the bottom surface onto the sliding surface 20a with an adhesive or the like. The rubber plate 24 is made of a rubber material having excellent wear resistance and durability, such as EP rubber, urethane rubber, polybutadiene rubber, and the like. By using the rubber material, the friction coefficient of the contact surface with the water intake pipe 12 is increased, and the frictional resistance with the water intake pipe 12 can be increased.
[0020]
When the contact surface of the rubber plate 24 with the water intake pipe 12 is provided with a number of minute uneven portions 24a as shown in FIG. 3 and the contact surface is roughened, the friction of the contact surface is further increased. The coefficient increases, and the frictional resistance can be further increased. The coefficient of friction can be adjusted by changing the material of the high frictional resistance layer 22, the uneven state (rough surface state) of the contact surface of the rubber plate 24, etc., up to a coefficient value of about 1.0. It can also be easily obtained.
[0021]
Thus, by providing the high frictional resistance layer 22 on the sliding surface 20a of the shooter 20, the frictional resistance when the water intake pipe 12 falls into the sea while sliding on the sliding surface 20a is increased. Since the braking force that opposes the dropping of the pipe 12 acts, the braking force required by the brake device 18, that is, the braking force that must be applied to the water intake pipe 12 by the device 18 can be reduced and relaxed. Therefore, the relationship between the friction coefficient on the surface of the high friction resistance layer 22 provided on the sliding surface 20a of the shooter 20 (contact surface with the water intake pipe 12) and the braking force required for the brake device 18 is as follows (2 ).
[0022]
[Expression 2]
T = Wh / e ^μθ (2)
[0023]
In the above equation (2),
T: Rear tension on the inlet side for introducing the water intake pipe 12 of the shooter 20 (= braking force required by the brake device 18)
W: Underwater weight per unit length of the intake pipe 12 h: Installation depth μ: Friction coefficient of the high frictional resistance layer 22 (when the intake pipe 12 is dropped into the sea)
θ: curvature of the high frictional resistance layer 22 (π / 2 in the case shown in FIG. 2)
[0024]
When the flexible intake pipe 12 having an underwater weight of 50 kg / m class is installed on the sea floor 14 in the sea area with a water depth of 100 m, it is necessary for the brake device 18 with the friction coefficient μ of the high friction resistance layer 22 as a parameter. Table 1 below shows the estimated braking force.
[0025]
[Table 1]

[0026]
As is clear from Table 1 above, the underwater weight of the water intake pipe 12 from when it is dropped into the sea until it reaches the bottom 14 is supported not only by the brake device 18 but also by the shooter 20. The force supporting the weight is distributed and the braking force required by the brake device 18 can be reduced. Further, the braking force can be reduced exponentially by increasing the friction coefficient of the high frictional resistance layer 22. For example, when the friction coefficient of the high friction resistance layer 22 is 0.5 as compared with the case where there is almost no frictional resistance, the braking force handled by the brake device 18 is about ½, and the friction coefficient is 1. In the case of 0, the braking force can be reduced to about 1/5. As a result, even if the laying water depth of the water intake pipe 12 becomes deep and the underwater weight increases, the braking force borne by the brake device can be reduced. It is possible to reduce the mechanical strength, reduce the size and weight of the brake device and reduce the cost, and reduce the construction work cost.
[0027]
4 shows that the contact surface of the high frictional resistance layer 22 with the water intake tube 12, that is, the contact surface of the rubber plate-like body 24 constituting the high frictional resistance layer 22 with the water intake tube 12. A plurality of protrusions 26 having an unequal triangular cross section are provided continuously along the dropping direction or the pulling direction (see FIG. 2 (a)) of the tube 12, and the length of the inclined side 26a located above the shooter of the protrusions The surface is roughened so that the length is shorter than the length of the inclined side 26b located below the shooter, so that the water intake pipe 12 is reverse in the direction of dropping and the normal in the direction of lifting. is there. That is, by providing such a protrusion 26 and roughening the contact surface, the friction resistance in the direction in which the water intake pipe 12 laid on the seabed 14 is pulled up to the laying ship 10 for repair or the like is obtained. The friction coefficient of the contact surface of the high frictional resistance layer 22 is given directionality so that the frictional resistance in the direction of dropping the intake pipe 12 from the laying ship 10 into the sea for laying is reduced. is there.
[0028]
As described above, when the direction of the friction coefficient of the high frictional resistance layer 22 is given direction, the water intake pipe 12 laid on the seabed 14 is damaged by dredging or the like, and is pulled up on the laying ship 10 for repair. The frictional resistance of the shooter 20 in the direction in which the water intake pipe 12 is lifted is smaller than the frictional resistance in the direction in which the water intake pipe 12 is dropped, so that the pulling force required for lifting the water intake pipe 12 is reduced. be able to. Therefore, when the take-up collection facility (not shown) for the water intake pipe 12 provided on the laying ship 10 and the long body storage portion 16 also serve as the recovery facility, the storage portion 16 is reduced in weight and size. This makes it possible to keep the cost of the recovery facility low, and the take-up force required for lifting the intake pipe 12 decreases, so that the intake pipe 12 is excessively stretched or subjected to side pressure during the recovery. There is no risk of damage and it is practical.
[0029]
When laying the water intake pipe 12 on the sea floor 14 using the seabed laying long body laying ship 10 of the present invention, the water intake pipe 12 is previously stored in the long body storage portion 16 as shown in FIG. The laying ship 10 is towed by a tug 11 along the predetermined laying route at sea. At the same time, the water intake pipe 12 is pulled out from the long body storage unit 16 and a brake device 18 applies a predetermined braking force to control the drop speed, and the shooter 20 gives a frictional resistance in the lifting direction. However, it is performed by dropping into the sea from the stern or bow of the laying ship 10 and laying it on the seabed 14. The intake pipe 12 laid on the seabed 14 is buried under the seabed at the same time as laying or after laying if necessary. In addition, the submarine laying long body laid on the seabed 14 by the laying ship 10 of the present invention is not limited to the water intake pipe 12 but can naturally be applied to other fluid transport pipes, submarine cables, and the like. It is.
[0030]
5A and 5B show a shooter 28 having a structure different from that of the shooter 20 shown in FIG. The shooter 28 is composed of a bend pipe having a split structure in which two iron semicircular

tubular bodies

30, 30 are detachably combined. The semicircular

tubular bodies

30 and 30 have

attachment rods

30a and 30a on both side edges, are formed in a quarter circle shape in the length direction, and maintain a constant curvature radius that is equal to or greater than the allowable curvature radius. It is formed in a substantially semicircular cross section that is bent outwardly in a convex shape. These semicircular

tubular bodies

30 and 30 are overlapped so that the semicircular recesses face each other, and are combined by bolting and fastening both

attachment rods

30a and 30a, and the water intake pipe 12 and the like are centered. A through hole 32 is provided through which the long undersea laying body passes. The through-hole 32 has an inner diameter that is about 10 to 20% larger than the outer diameter of the submarine laying long body, and the rubber plate-like body constituting the high friction resistance layer 22 on the inner peripheral surface, that is, the sliding surface. (Rubber sheet) 24 is lined. The inner surface of the rubber plate-like body 24, that is, the contact surface with the long seabed laying body is subjected to the roughening treatment for increasing the frictional resistance with the long seabed laying body as necessary. May be.
[0031]
When such a shooter 28 is used, it becomes possible to drop the seabed laid elongate body into the sea by bringing it into contact with the high frictional resistance layer 22 of the shooter 28. Therefore, it is preferable because the frictional resistance when dropping the long submarine laying body can be further increased, the braking force required by the brake device 18 can be reduced, and the burden can be further reduced.
[0032]
The high frictional resistance layer 22 is configured by providing a rubber plate-like body 24 on a sliding surface that comes into contact with a long seabed laid long body such as the water intake pipe 12 of the

shooters

20 and 28. In addition, the high frictional resistance layer (not shown) is subjected to a roughening treatment such as providing the minute irregularities 24a and the protrusions 26 having an irregular cross-section of the triangle directly on the sliding surface itself. May be provided.
[0033]
【The invention's effect】
As described above, according to the submarine laying long body laying ship of the present invention, the submarine laying long body is placed on the sliding surface that comes into contact with the submarine laying long body of the shooter that drops the submarine laying long body into the sea. Since a high frictional resistance layer is provided to increase the frictional resistance, even if the underwater installation elongate has a deeper water depth and the underwater installation elongate weight increases during installation, the underwater weight is It becomes possible to support the vehicle, and the braking force required by the brake device can be reduced. Therefore, it is possible to reduce the power for driving and controlling the brake device and the mechanical strength of each mechanism, and the brake device can be reduced in size, weight, and cost.
[0034]
In addition, the gripping force of the long submarine laying body is reduced, and excessive lateral pressure exceeding the allowable lateral pressure does not act on the long submarine laying body. Thus, it is possible to safely lay the seabed laying long body on the seabed in a deep water area without causing deformation or damage.
[0035]
Further, in the submarine laying long body laying ship of the present invention, the submarine laying long body laid on the sea floor is used as the high friction resistance layer provided on the sliding surface in contact with the seabed laying long body of the shooter. The friction coefficient may be given directionality so that the frictional resistance in the direction of pulling up is smaller than the frictional resistance in the direction of dropping the seabed laying long body from the laying ship into the sea. In this way, when the submarine laying long body laid on the seabed is lifted on a laying ship for repair or the like, the frictional resistance of the shooter in the direction of lifting the submarine laying long body is reduced. It is possible to reduce the take-up force required for lifting the laid long body. Therefore, it is possible to reduce the size of the take-up and recovery facility for the long seabed installed on the laying ship, reduce the cost of the recovery equipment, and take-up force required to lift the long seabed laid body. Therefore, there is no risk that the submarine laying long body will be damaged due to excessive stretching or lateral pressure during its recovery.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view showing a usage state of a submarine laid long body laid ship of the present invention.
FIGS. 2A and 2B show an outline of a shooter used in a submarine laying long body laying ship according to the present invention. FIG. 2A is a front view, FIG. 2B is a right end view, and FIG. It is the front view which expanded the part.
FIG. 3 is an enlarged front view of a part of a modification of the high frictional resistance layer of FIG.
FIG. 4 is an enlarged front view of a part of a further modification of the high frictional resistance layer of FIG.
FIG. 5 shows an outline of a modified example of a shooter used in a submarine laying long body laying ship of the present invention, where (A) is a front view and (B) is a right end view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Submarine installation long body installation ship 11 Dredger 12 Intake pipe 14 Submarine 16 Long body storage part 18 Brake device 20 Shuta 20a Sliding surface 22 High friction resistance layer 24 Rubber plate-like body 24a Minute uneven part 26 Cross section unequal triangular shape Projection body 26a Inclined side 26b Inclined side 28 Shuter 30 Semicircular tubular body 30a Mounting rod 32 Through hole

Claims

A submarine installation length comprising a long body storage section for storing a submarine installation long body, a brake device for controlling a speed of dropping the submarine installation long body into the sea, and a shooter for dropping the submarine installation long body into the sea In the body laying ship, a high friction resistance layer for increasing a frictional resistance with the seabed laying long body is provided on a sliding surface contacting the seabed laying long body of the shooter, and the high friction resistance layer The direction of the friction coefficient is such that the frictional resistance in the direction of lifting the submarine laid long body laid on the seabed to the laid ship is smaller than the frictional resistance in the direction of dropping the submarine laid longbody from the laid ship into the sea. Submarine laying long body laying, characterized by having a property .

Provided on the contact surface of the high friction resistance layer with the seabed laying elongated body is a plurality of unequal triangular triangular projections along the dropping or lifting direction of the seabed laying elongated body, above the shooter of the protrusion 2. The submarine laying long body laying ship according to claim 1, wherein the length of the inclined side located is shorter than the length of the inclined side located below the shooter.